CN115220143A

CN115220143A - Method and apparatus for manufacturing optical member

Info

Publication number: CN115220143A
Application number: CN202210828748.5A
Authority: CN
Inventors: 芦田丈行; 西幸二朗
Original assignee: Sumitomo Chemical Co Ltd
Current assignee: Sumitomo Chemical Co Ltd
Priority date: 2017-10-05
Filing date: 2018-10-04
Publication date: 2022-10-21
Also published as: WO2019070033A1

Abstract

[ problem ] to provide a method and an apparatus for manufacturing an optical member with little adhesion of powder such as polishing dust. [ solution ] A method for manufacturing an optical member includes: a step for preparing a laminate (100) which has an optical film (50) and a pressure-sensitive adhesive layer (80) provided on one surface of the optical film (50), and to the end face (E) of which powder (f) is adhered; and a step of removing the powder (f) from the end face (E) of the laminate (100) by causing the dry ice particles (d) to strike the end face (E).

Description

Method and apparatus for manufacturing optical member

The present application is a divisional application of an application having an application date of 2018, 10/month, and 4/month, an application number of 201880064320.X, and an invention name of "method and apparatus for manufacturing optical member".

Technical Field

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

Background

Conventionally, an optical member including an optical film such as a polarizing plate and an adhesive layer is known.

As a method for obtaining an optical member having a desired size, a method is known in which a raw material laminate having an optical film and an adhesive layer is cut with a laser or a blade (see patent documents 1 and 2).

Documents of the prior art

Patent document

Patent document 1: WO2014/189078 publication

Patent document 2: japanese patent laid-open publication No. 2009-86675

Disclosure of Invention

Problems to be solved by the invention

However, in recent years, the requirements for dimensional accuracy of optical members using an optical film and an adhesive layer have become more stringent. Therefore, it is difficult to obtain desired dimensional accuracy only by cutting the raw material laminated body. Then, the end face of the cut laminate may be subjected to processing such as grinding and polishing.

However, when the end face of the laminate is subjected to a process such as polishing, powder such as polishing dust may adhere to the end face of the laminate. If the powder remains in the laminate, it is not preferable because it causes contamination of the final product including the laminate.

The present invention has been made in view of the above problems, and an object thereof is to provide a method and an apparatus for manufacturing an optical member with less adhesion of powder such as polishing dust.

Means for solving the problems

The method for manufacturing an optical member according to the present invention includes: a step (preparation step) of preparing a laminate having an optical film and a pressure-sensitive adhesive layer provided on one surface of the optical film, and having a powder adhered to an end surface thereof; and a step (impact step) of removing the powder from the end face of the laminate by causing dry ice particles to impact the end face.

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

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

This makes it possible to suitably remove powder such as grinding dust and to suppress the adhesive on the end face from being damaged.

In the impact step, the dry ice particles may be made to impact an end face of a laminated structure in which a plurality of the laminated bodies are laminated.

This enables a large amount of processing of the laminate.

Further, the dry ice particles may be caused to strike a part of the end face while at least one selected from the group consisting of cutting, and grinding is performed on the other part of the end face of the laminate.

This allows a plurality of steps to be performed simultaneously and in parallel, and the process time can be shortened.

In the preparation step, the end face may be subjected to at least one treatment selected from the group consisting of cutting, and polishing, and when the dry ice particles are caused to strike a part of the end face, the end face may not be subjected to any one treatment selected from the group.

This makes it possible to distinguish between an atmosphere (space) in which the powder is removed by the impact of the dry ice particles and an atmosphere (space) in which the processing of the powder occurs, and thus it is possible to suppress the powder produced by the processing of the end face from contaminating the portion impacted by the dry ice.

The optical film may be at least one selected from a polarizing plate, a protective film, a retardation film, a brightness enhancement film, a window film, and a touch sensor; a laminated film containing 2 or more of at least 1 kind selected from the group, or a laminated film containing at least 2 kinds selected from the group.

The relative humidity of the atmosphere in the impact step may be 30 to 75%.

The optical member manufacturing apparatus according to the present invention includes: an end face processing unit for cutting, chipping, or polishing an end face of a laminate having an optical film and a pressure-sensitive adhesive layer provided on one surface of the optical film; and a dry ice particle supply unit configured to cause dry ice particles to strike a portion of the laminate body that is processed into the end face processed portion.

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

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present invention, a method and an apparatus for manufacturing an optical member with less adhesion of powder such as polishing dust can be provided.

Drawings

Fig. 1 (a) and (b) are cross-sectional views of a laminate 100 according to 1 embodiment of the present invention.

Fig. 2 (a) and (b) are sectional views of another example of the laminate.

Fig. 3 is a schematic configuration diagram of a dry ice particle supply unit.

Fig. 4 is a conceptual diagram illustrating a mode of causing dry ice particles to strike an end face of a laminated structure 120 having a plurality of laminates 100.

Fig. 5 is a perspective view of an apparatus for manufacturing an optical member according to 1 embodiment of the present invention.

Fig. 6 is a perspective view showing another example of the end-face processed portion in fig. 5.

Fig. 7 is a conceptual diagram illustrating a mode in which ice particles are caused to strike an inner end face of the laminated structure 120 having the through-holes H'.

Detailed Description

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

(preparation of a laminate having powder adhered to the end face)

First, as shown in fig. 1 (a), a laminate 100 having an optical film 50 and a pressure-sensitive adhesive layer 80 provided on one surface of the optical film 50 and having powder f adhered to an end face E thereof is prepared. The end face E is not limited to the outer end face 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, powder f such as a pore opening dust may adhere to the inner wall of the hole H, that is, the inner end face E of the laminate 100.

(optical film)

Optical film 50 refers to a film that transmits at least a portion of visible light.

Examples of the optical film 50 include a polarizing plate, a protective film, a retardation film, a brightness enhancement film, a window film, and a touch sensor, and the optical film 50 may have a single type of laminated structure including a plurality of these films or may have a laminated structure including a plurality of types of these films.

(polarizing plate)

The polarizing plate is a film in which the transmittances of linearly polarized light are different from each other in 2 directions orthogonal to each other in a plane. As the material of the polarizing plate, known materials conventionally used in the production of polarizing plates can be used, and examples thereof include polyvinyl alcohol resins, polyvinyl acetate resins, ethylene/vinyl acetate (EVA) resins, polyamide resins, polyester resins, and the like. Among them, polyvinyl alcohol resins are preferred. These resin films are stretched and then dyed with iodine or a dichroic dye and treated with boric acid, whereby a film-shaped polarizing plate (film-type polarizing plate) can be obtained.

The thickness of the film-type polarizing plate may be, for example, 1 to 75 μm.

In addition, another example of the polarizing plate may be a liquid crystal coating type polarizing plate made of a liquid crystal compound. The liquid crystal-coated polarizing plate can be produced, for example, by using an appropriate substrate and coating a liquid crystal polarizing composition on the substrate. An alignment film may be formed before the liquid crystal polarizing composition is coated on the substrate. The liquid crystal polarizing composition may include a liquid crystal compound and a dichroic dye compound. The liquid crystal compound may have a property of exhibiting a liquid crystal state, and particularly, a liquid crystal state having a high order such as a smectic phase is preferable because the obtained liquid crystal-coated polarizing plate can exhibit high polarizing performance. The liquid crystalline compound preferably has a polymerizable functional group. The dichroic dye compound is a dye that exhibits dichroism by being aligned together with the liquid crystal compound, and the dichroic dye itself may have liquid crystal properties or may have a polymerizable functional group. Any compound contained in the liquid crystal polarizing composition preferably has a polymerizable functional group. The liquid crystal polarized light composition may further include an initiator, a solvent, a dispersant, a leveling agent, a stabilizer, a surfactant, a crosslinking agent, a silane coupling agent, and the like.

Here, a typical example of a method for manufacturing a liquid crystal coating type polarizing plate by forming an alignment film on a substrate and coating a liquid crystal polarizing composition on the substrate on which the alignment film is formed is shown.

The liquid crystal coated polarizing plate produced by this method can be made thinner than the film-type polarizing plate. The thickness of the liquid crystal coated light-type polarizing plate is 0.5 to 10 μm, preferably 1 to 5 μm.

The alignment film can be formed on the substrate by, for example, applying an alignment film-forming composition to the substrate to form a coating film, and imparting alignment properties to the coating film by rubbing, polarized light irradiation, or the like. The alignment film forming composition may contain an alignment agent, and may contain a solvent, a crosslinking agent, an initiator, a dispersant, a leveling agent, a silane coupling agent, and the like in addition to the alignment agent. Examples of the orientation agent include polyvinyl alcohols, polyacrylates, polyamide acids, and polyimides. When photo-alignment is used as a method for imparting the alignment property, an alignment agent containing a cinnamate group is preferable.

The alignment agent may be a polymer. The weight average molecular weight of the polymer orientation agent is about 10000 to 1000000. The thickness of the alignment film formed on the substrate is preferably 5nm to 10000nm, and particularly preferably 10 to 500nm because sufficient alignment regulating force can be exhibited.

A liquid crystal polarizing composition is applied to a substrate on which an alignment film is formed, and dried as necessary, thereby forming a coating film of the liquid crystal polarizing composition, and a liquid crystal coating type polarizing plate is produced from the coating film of the liquid crystal polarizing composition.

The liquid crystal polarizing plate thus manufactured can be peeled from the substrate. As a method for peeling the liquid crystal coated polarizing plate from the substrate, for example, a method of obtaining a laminate of the liquid crystal coated polarizing plate and the second substrate by bonding the second substrate to the surface of the liquid crystal coated polarizing plate on which the substrate is not laminated and then peeling the substrate is used, and the liquid crystal coated polarizing plate may be transferred to the second substrate or may be left laminated on the substrate without being transferred to the second substrate. The substrate or the second substrate preferably functions as a transparent substrate for a protective film, a retardation plate, or a window film.

(protective film)

The protective film is a transparent film that prevents damage such as damage to other optical films such as a polarizing plate and/or an optical device (liquid crystal cell or the like) to which the laminate 100 is attached later. The protective film may be various transparent resin films.

Here, a protective film for protecting the polarizing plate is described. Examples of the resin forming the protective film are:

cellulose resins typified by triacetyl cellulose;

polyolefin resins typified by polypropylene resins;

a cycloolefin resin typified by a norbornene resin;

acrylic resins typified by polymethyl methacrylate resins; and

a polyester resin typified by a polyethylene terephthalate resin. Among these, cellulose-based resins are representative.

The thickness of the protective film may be, for example, 5 to 90 μm.

The protective film may contain, if necessary, plasticizers, ultraviolet absorbers, infrared absorbers, pigments, colorants such as dyes, fluorescent brighteners, dispersants, heat stabilizers, light stabilizers, antistatic agents, antioxidants, lubricants, solvents, and the like.

A hard coat layer may be provided on at least one surface of the protective film to improve scratch resistance of the surface of the protective film. The thickness of the hard coat layer is usually in the range of 2 to 100. Mu.m. When the thickness of the hard coat layer is less than 2 μm, it is difficult to secure sufficient scratch resistance, and when it exceeds 100 μm, bending resistance is lowered, and when a protective film is bonded to a polarizing plate or the like, a problem of curling due to curing shrinkage may occur.

The hard coat layer may be formed using a hard coat composition containing a reactive material that forms a cross-linked structure by irradiation of an active energy ray or a thermal energy ray. Among these, a hard coat layer obtained by irradiation with active energy rays is preferable. The active energy ray is defined as: the active species generating compound is decomposed and energy rays of the active species are generated. Examples of the active energy rays include visible light, ultraviolet rays, infrared rays, X-rays, α -rays, β -rays, γ -rays, and electron beams. Among these, ultraviolet rays are particularly preferable. The hard coat composition preferably contains at least 1 of a radical polymerizable compound and a cation polymerizable compound. These radically polymerizable compounds and oligomers obtained by partially polymerizing a cationically polymerizable compound may be contained in the hard coat composition.

First, a radical polymerizable compound will be described.

The radical polymerizable compound is a compound having a radical polymerizable group. The radical polymerizable group may be any functional group capable of undergoing a radical polymerization reaction, and examples thereof include a group containing a carbon-carbon unsaturated double bond, and examples thereof include a vinyl group and a (meth) acryloyl group. When the radical polymerizable compound has 2 or more radical polymerizable groups in 1 molecule, the radical polymerizable groups may be the same or different from each other. When the radical polymerizable compound has 2 or more radical polymerizable groups in 1 molecule, the hardness of the obtained hard coat layer tends to be improved. Among the above radical polymerizable compounds, compounds having a (meth) acryloyl group are preferable from the viewpoint of high reactivity, and examples thereof include compounds called multifunctional acrylate monomers having 2 to 6 (meth) acryloyl groups in 1 molecule, epoxy (meth) acrylates, urethane (meth) acrylates, and oligomers called polyester (meth) acrylates having a plurality of (meth) acryloyl groups in the molecule and having a molecular weight of from several hundred to several thousand. Among the compounds having a (meth) acryloyl group, 1 or more selected from epoxy (meth) acrylates, urethane (meth) acrylates, and polyester (meth) acrylates are preferable.

Next, the cationic polymerizable compound will be described.

The cationically polymerizable compound is a compound having a cationically polymerizable group such as an epoxy group, an oxetane group, or a vinyl ether group. The number of the cationically polymerizable groups contained in 1 molecule of the cationically polymerizable compound is preferably 2 or more, and more preferably 3 or more, from the viewpoint of improving the hardness of the hard coat layer to be obtained. The cationically polymerizable compound is preferably a compound having at least 1 cationically polymerizable group of an epoxy group and an oxetane group. The cyclic ether group of the epoxy group or the oxetane group has an advantage of small shrinkage accompanying the polymerization reaction. Among compounds having an epoxy group among cyclic ether groups, compounds having various structures are readily available on the market, and are less likely to adversely affect the durability of the obtained hard coat layer. When a radically polymerizable compound and a cationically polymerizable compound are used in combination in the hard coat composition, the compound having an epoxy group has an advantage that the compatibility with the radically polymerizable compound can be easily controlled. In addition, an oxetanyl group among cyclic ether groups has the following advantages compared with an epoxy group: the polymerization degree tends to be high, the toxicity is low, the network formation rate of the cationic polymerizable compound of the obtained hard coat layer is increased, and the unreacted monomer in the region mixed with the radical polymerizable compound does not remain in the film but forms an independent network.

Examples of the compound having an epoxy group include

Polyglycidyl ethers of polyhydric alcohols having alicyclic rings;

alicyclic epoxy resins obtained by epoxidizing compounds containing a cyclohexene ring or cyclopentene ring with a suitable oxidizing agent such as hydrogen peroxide or a peroxy acid;

polyglycidyl ethers of aliphatic polyols 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;

glycidyl ethers produced by the reaction of a bisphenol such as bisphenol a, bisphenol F, hydrogenated bisphenol a, or a derivative thereof such as an alkylene oxide adduct or a caprolactone adduct with epichlorohydrin; and

and glycidyl ether type epoxy resins derived from bisphenols, which are phenolic 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) can be selected and used depending on the kind of the polymerizable compound contained in the hard coat composition. These polymerization initiators are decomposed by at least one of irradiation with active energy rays and heating to generate radicals or cations, and radical polymerization or cationic polymerization is performed.

The radical polymerization initiator may be one which can release a substance for initiating radical polymerization by at least either irradiation with an active energy ray or heating. Examples of the thermal radical polymerization initiator include organic peroxides such as hydrogen peroxide and perbenzoic acid, and azo compounds such as azobisbutyronitrile.

As the active energy ray radical polymerization initiator, there are a Type1 radical polymerization initiator which generates radicals by decomposition of molecules and a Type2 radical polymerization initiator which generates radicals by hydrogen abstraction Type reaction in coexistence with tertiary amine, and they can be used alone or in combination.

The cationic polymerization initiator may be any initiator that can release a substance that initiates cationic polymerization by at least either irradiation with an active energy ray or heating. As the cationic polymerization initiator, aromatic iodonium salts, aromatic sulfonium salts, cyclopentadienyl iron (II) complexes, and the like can be used. They initiate cationic polymerization by either or both of irradiation with active energy rays and heating depending on the structure.

The polymerization initiator may be contained in an amount of 0.1 to 10 wt% based on the total weight of the hard coat composition. When the content of the polymerization initiator is less than 0.1% by weight, sufficient curing cannot be performed, and the mechanical properties of the hard coat layer finally obtained tend to be deteriorated or the adhesion between the hard coat layer and the protective film tends to be insufficient. When the amount exceeds 10% by weight, poor adhesion, cracking, and curling due to curing shrinkage during formation of the hard coat layer may occur.

The hard coating composition may further include one or more selected from a solvent and an additive.

The solvent can dissolve or disperse the polymerizable compound and the polymerization initiator, and can be used without limitation if it is known as a solvent for a hard coating composition in the art.

The additive is inorganic particles, a leveling agent, a stabilizer, a surfactant, an antistatic agent, a lubricant, an antifouling agent and the like.

Next, a method of bonding the protective film to the polarizing plate will be described.

The protective film of the polarizing plate is preferably attached to the polarizing plate with an adhesive. Examples of the adhesive include:

aqueous adhesives using aqueous polyvinyl alcohol resin solutions, aqueous two-pack polyurethane emulsion adhesives, and the like;

an active energy ray-curable adhesive such as a curable composition containing a polymerizable compound and a photopolymerization initiator, a curable composition containing a photoreactive resin, and a curable composition containing a binder resin and a photoreactive crosslinking agent is used.

The polyvinyl alcohol resin contained in the aqueous polyvinyl alcohol resin solution used as the adhesive includes: vinyl alcohol homopolymers obtained by saponifying polyvinyl acetate, which is a homopolymer of vinyl acetate, vinyl alcohol copolymers obtained by saponifying copolymers of vinyl acetate and other monomers copolymerizable therewith, and modified polyvinyl alcohol polymers obtained by partially modifying hydroxyl groups thereof. The water-based adhesive may further contain a polyaldehyde, a water-soluble epoxy compound, a melamine compound, a zirconium oxide compound, a zinc compound, or the like as an additive.

The active energy ray-curable adhesive used as the adhesive includes the same adhesive as the adhesive containing a reactive material that forms a crosslinked structure by irradiation with an active energy ray exemplified as one of the hard coat compositions.

Although the method of using a resin film as a protective film (or a protective film having a hard coat layer) and bonding the protective film to a polarizing plate has been described above, a protective film may be formed by directly laminating a thinner protective layer to a polarizing plate instead of the resin film.

As a method of directly laminating a thinner protective layer on a polarizing plate, for example, when a coating film containing an active energy ray-curable resin is formed on the surface of the polarizing plate and the coating film is cured by irradiation with an active energy ray (UV or the like), a protective film thinner than a conventional protective film can be directly formed on the surface of the polarizing plate. Examples of the active energy ray-curable resin include resins exemplified as one of the hard coat compositions and containing a reactive material that forms a crosslinked structure upon irradiation with an active energy ray.

(Window film)

On the other hand, a transparent protective film that prevents damage such as damage to an optical device (a liquid crystal cell or the like) to which the laminate 100 is attached later is referred to as a window film. For example, when the optical film 50 has a laminated structure including a plurality of films, the window film is disposed on the outermost surface of the plurality of films on the side opposite to the surface on which the pressure-sensitive adhesive layer 80 is provided.

The window film is disposed on the viewing side of the flexible image display device, and functions to protect other components from external impact or environmental changes such as temperature and humidity. Glass has been conventionally used as such a protective layer, but a window film in a flexible image display device has a flexible characteristic, unlike glass, which is rigid and hard. The window film comprises a flexible transparent substrate and may also comprise a hard coat layer on at least one side.

(transparent substrate)

A transparent substrate that can be used as a window film will be described.

The transparent base material has a visible light transmittance of 70% or more, preferably 80% or more. Any material may be used for the transparent substrate as long as it is a polymer film having transparency. Specifically, the film may be formed of the following polymers or the like, or may be formed by mixing 2 or more kinds of these polymers alone or in combination:

polyolefins such as cycloolefin derivatives having a unit containing a monomer of polyethylene, polypropylene, polymethylpentene, norbornene, or cycloolefin;

(modified) celluloses such as diacetylcellulose, triacetylcellulose, and propionyl cellulose;

acrylic acids such as methyl methacrylate (co) polymers;

polystyrenes such as styrene (co) polymers;

acrylonitrile-butadiene-styrene copolymers, acrylonitrile-styrene copolymers;

ethylene-vinyl acetate copolymers;

polyvinyl chloride-based polymers and polyvinylidene chloride-based polymers;

polyesters such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polycarbonate and polyarylate;

polyamides such as nylon;

polyimides, polyamide imides, polyether imides;

polyether sulfones, polysulfones;

polyvinyl alcohols, polyvinyl acetals;

polyurethanes;

epoxy resins.

Further, an unstretched film, a uniaxially stretched film, or a biaxially stretched film may be used as the film. Among the transparent substrates of the polymers exemplified above, polyamide films, polyamideimide films, polyimide films, polyester films, olefin films, acrylic films, and cellulose films are preferable, which are excellent in transparency and heat resistance. In addition, the transparent base material is preferably dispersed with inorganic particles such as silica, organic fine particles, rubber particles, and the like. Further, a colorant such as a pigment or a dye, a fluorescent whitening agent, a dispersant, a plasticizer, a heat stabilizer, a light stabilizer, an infrared absorber, an ultraviolet absorber, an antistatic agent, an antioxidant, a lubricant, a solvent, and the like may be contained. The thickness of the transparent substrate is 5 to 200 μm, preferably 20 to 100 μm.

(hard coating)

A material having a hard coat layer provided on at least one surface of the transparent substrate may be used as the window film. As the hard coat layer, the same hard coat layer as that of the above-described protective film can be used.

(retardation film)

The retardation film is a transparent film having refractive indices different from each other in 2 directions orthogonal to each other in a plane, and gives a retardation to transmitted light.

Examples of the material of the retardation film include polycarbonate resin films, polysulfone resin films, polyethersulfone resin films, polyarylate resin films, and norbornene resin films.

These resin films can be given a desired phase difference by stretching.

In addition, a retardation film which is easily available from the market may be used.

The thickness of the retardation film may be, for example, 0.5 to 80 μm.

(Brightness improving film)

The luminance improving film is a film that transmits polarized light in-plane parallel to a first direction and reflects polarized light in-plane parallel to a second direction orthogonal to the first direction. In the case where the optical film used in the present invention has a polarizing plate, the first direction is preferably aligned with the transmission axis of the polarizing plate.

The luminance improving film may be a multilayer laminate in which a layer having birefringence and a layer having substantially no birefringence are alternately laminated. Examples of the material of the layer having birefringence are a polyester of naphthalenedicarboxylic acid (e.g., polyethylene naphthalate), polycarbonate, and an acrylic resin (e.g., polymethyl methacrylate), and an example of the layer having substantially no birefringence is a copolyester of naphthalenedicarboxylic acid and terephthalic acid.

The thickness of the luminance improving film may be, for example, 10 to 50 μm.

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

(bonding in optical film)

When the optical film 50 has a laminated structure including a plurality of films, the films may be bonded to each other with an adhesive. The adhesive is not particularly limited, and may be any of the aqueous adhesive and active energy ray-curable adhesive described above.

Further, an adhesive may be used as the adhesive. This adhesive will be described later.

The thickness of the adhesive may be set to 1 to 200 μm.

(thickness of optical film in case of laminate)

The overall thickness of the optical film 50 when the optical film 50 has a laminated structure including a plurality of films may be 10 to 1200 μm.

(adhesive layer)

As described above, the laminate used in the present invention includes an optical film and a pressure-sensitive adhesive layer provided on one surface of the optical film. The pressure-sensitive adhesive layer is a layer formed using a pressure-sensitive adhesive. Here, the adhesive will be explained.

The pressure-sensitive adhesive is a pressure-sensitive adhesive which is in a soft solid (viscoelastic body) state in a temperature range around room temperature (e.g., 25 ℃), and has a property of simply adhering to an adherend by pressureThe nature of the substance. The adhesives described herein are prepared from "c.a. dahlquist, addition: fundamental and Practice ", mcLaren&Sons, (1966), definition of P.143", in general, can be such that it satisfies the complex tensile modulus E ^＊ (1Hz)＜10 ⁷ dyne/cm ² A material having the above properties (typically, a material having the above properties at 25 ℃). The pressure-sensitive adhesive in the art disclosed herein can be also understood as a solid component (nonvolatile component) of the pressure-sensitive adhesive composition or a component of the pressure-sensitive adhesive layer.

Examples of binders are: a composition comprising an acrylic resin, a styrene resin, a silicone resin, etc. as a base polymer and, added thereto, a crosslinking agent such as an isocyanate compound, an epoxy compound, an aziridine compound, etc. In this specification, the "base polymer" of the pressure-sensitive adhesive means a main component of a rubbery polymer contained in the pressure-sensitive adhesive. The rubbery polymer is a polymer that exhibits rubber elasticity in a temperature range around room temperature. In this specification, the term "main component" means a component containing more than 50% by weight unless otherwise specified.

The thickness of the adhesive may be set to 1 to 40 μm.

(thickness of optical film in case of laminate)

The adhesive layer 80 is provided on at least one side of the optical film (single-layer structure or laminated structure) 50.

As the binder, the above-mentioned binder can be used.

(isolation film)

The laminate 100 may have a separator 90 on the side of the adhesive layer 80 opposite the side in contact with the optical film 50.

The release film 90 is a film having a weaker adhesion to the pressure-sensitive adhesive layer 80 than the optical film 50. The separator 90 protects the surface of the pressure-sensitive adhesive layer 80 during transportation and 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 pressure-sensitive adhesive layer 80. The release film 90 can be easily peeled off from the adhesive layer 80 when the adhesive layer 80 is attached to another member.

The separator is not necessarily transparent, but is preferably transparent. An example of a material for the separator is polyethylene terephthalate. The thickness of the separator may be set to 1 to 40 μm.

(protective film)

The laminate 100 may have a pellicle 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 has the following functions: a function of suppressing damage to the optical device and/or the optical film 50 during processing of the laminate 100, during attachment of the laminate 100 to an optical device (such as a liquid crystal cell), during transportation of the optical device to which the laminate 100 is attached, or the like.

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 may be set to 1 to 40 μm.

The protective film 70 may be a film that protects the optical film 50 until the time of use of a product using the optical film 50. In this case, even after the optical film 50 is attached to an optical device (a liquid crystal cell or the like) via the pressure-sensitive adhesive layer 80, the protective film 70 is not peeled off from the optical film 50.

The protective film 70 may be affixed to the optical film 50 by means of an adhesive layer or with self-adhesion based on electrostatic adsorption.

Specific examples of the laminated structure of the laminate 100 are shown in fig. 2 (a) and (b).

In the laminate 100 of fig. 2 (a), the protective film 70, the protective film 2, the polarizing plate 3, the protective film 2, the adhesive layer 80, and the separator 90 are laminated in this order. The protective film 2, the polarizing plate 3, and the protective film 2 constitute an optical film 50.

In the laminate 100 of fig. 2 (b), the pellicle film 70, the protective film 2, the polarizing plate 3, the adhesive layer 80, and the separator 90 are laminated in this order. The protective film 2 and the polarizing plate 3 constitute an optical film 50. Although not shown, in any of the examples, the films in each optical film 50 may be bonded to each other 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 used in a flexible image display device which can be bent or the like.

As for the flexible image display device, an image display device including a laminate for a flexible image display device and an organic EL display panel is a typical example. In this typical example, a laminate for a flexible image display device is generally disposed on the viewing side of the organic EL display panel, and the flexible image display device is configured to be bendable. The laminate for a flexible image display device may include a window film, a circularly polarizing plate, and a touch sensor in any order, but is preferably configured in the order of laminating the window film, the circularly polarizing plate, and the touch sensor, or in the order of laminating the window film, the touch sensor, and the circularly polarizing plate from the observation side. The presence of the circularly polarizing plate on the observation side of the touch sensor is preferable because the pattern of the touch sensor is difficult to be visually recognized and visibility of a display image is improved. The members may be laminated using an adhesive, or the like. The window film may further include a light-shielding pattern formed on at least one surface of any one of the layers of the window film, the circularly polarizing plate, and the touch sensor.

(circularly polarizing plate)

The circularly polarizing plate is a functional film having a function of transmitting only right or left circularly polarized light components by laminating a λ/4 phase difference plate as a phase difference film on a linear polarizing plate. When external light entering the display device passes through the circularly polarizing plate disposed on the observation side, the external light is converted into right circularly polarized light and emitted to the organic EL panel side. When the right circularly polarized light is reflected (reflected light) by the metal electrode of the organic EL panel, the reflected light becomes left circularly polarized light. Since the left circularly polarized light cannot transmit the circularly polarized plate, as a result, the reflected light is not emitted to the outside of the display device. With such a function, only the light emitting component of the organic EL is observed on the display panel of the display device, and only the light emitting component is transmitted, whereby the influence of the reflected light can be prevented, and the image can be easily observed.

In order to realize the circularly polarized light function, the absorption axis of the linear polarizing plate and the slow axis of the λ/4 phase difference plate must theoretically be 45 °, but practically 45 ± 10 °. The linearly polarizing plate and the λ/4 phase difference plate do not necessarily have to be stacked 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 realize completely circularly polarized light at all wavelengths, this is not necessarily required in practice, and the circularly polarizing plate of the present invention also includes an elliptically polarizing plate. Preferably, a λ/4 phase difference plate is further laminated on the observation side of the linear polarizing plate to circularly polarize the emitted light, thereby improving the observation performance in a state where the polarized sunglasses are worn.

The linearly polarizing plate is a functional layer having a function of transmitting light vibrating in the transmission axis direction, but shielding polarized light of a vibration component perpendicular thereto. The linear polarizing plate is generally configured to include a polarizer and a protective film attached to at least one surface of the polarizer. The polarizing plate may be any of the above-described film-type polarizing plate or liquid crystal coating-type polarizing plate. The protective film described above may be used as the protective film. The thickness of the linear polarizer constituting the circularly polarizing plate is preferably 200 μm or less, and more preferably 0.5 to 100 μm. When the thickness exceeds 200 μm, flexibility (flexibility) of the laminate applicable to a flexible image display device may decrease. By appropriately adjusting the thicknesses of the polarizing plate and the protective film, the thickness of an appropriate linear polarizing plate can be adjusted.

The λ/4 retardation plate as a retardation film is a retardation plate called a 1/4 wavelength plate, and gives a phase difference of pi/2 (= λ/4) to a polarization plane of incident light. A λ/4 phase difference plate can be prepared by selecting a phase difference film having such properties from the above-mentioned phase difference films, and as another example, a liquid crystal coating type phase difference plate formed by coating a liquid crystal composition can be used as the λ/4 phase difference plate. As will be described later, a liquid crystal coated retardation plate formed by coating the liquid crystal composition can provide a λ/4 retardation plate having an extremely small thickness. Therefore, the liquid crystal-coated retardation plate is particularly preferable as a λ/4 retardation plate of a circularly polarizing plate constituting a laminate for a flexible image display device.

Here, a liquid crystal composition for forming the λ/4 phase difference plate will be described.

The liquid crystal composition includes a liquid crystal compound having a property of exhibiting a liquid crystal state such as a nematic state, a cholesteric state, or a smectic state. The liquid crystalline compound has a polymerizable functional group. The liquid crystal composition may also comprise a plurality of liquid crystal compounds, and in the case of comprising a plurality of liquid crystal compounds, at least 1 of the liquid crystal compounds has a polymerizable functional group. The liquid crystal composition may further include an initiator, a solvent, a dispersant, a leveling agent, a stabilizer, a surfactant, a crosslinking agent, a silane coupling agent, and the like. The liquid crystal coated retardation plate can be produced by coating and curing a liquid crystal composition on an alignment film of a substrate on which an alignment film is formed in advance to form a liquid crystal retardation layer on the alignment film, in the same manner as described in the method for producing a liquid crystal polarizing plate. The liquid crystal coating type retardation plate can be formed thinner than the stretched type retardation plate. The thickness of the liquid crystal polarizing layer is 0.5 to 10 μm, preferably 1 to 5 μm. The liquid crystal coating type phase difference plate may be peeled from a substrate and transferred to be laminated, or the substrate may be directly laminated. The substrate preferably functions as a protective film or a transparent substrate for a retardation plate.

In many of the materials constituting the retardation film, the shorter the wavelength, the larger the birefringence and the longer the wavelength, the smaller the birefringence. In this case, since a retardation of λ/4 cannot be realized in all visible light regions, an in-plane retardation of λ/4 is often designed to be 100 to 180nm, preferably 130 to 150nm, in the vicinity of 560nm, which has high visual visibility. The use of an inverse dispersion λ/4 phase difference plate using a material having a birefringence wavelength dispersion characteristic opposite to that of the usual one is preferable because visibility can be improved. As such a material, a material described in japanese patent application laid-open No. 2007-232873 and the like is preferably used in the case of a stretched retardation plate, and a material described in japanese patent application laid-open No. 2010-30979 is preferably used in the case of a liquid crystal coated retardation plate.

As another method for forming a preferable retardation film constituting a circularly polarizing plate, a technique of obtaining a wide-band λ/4 retardation plate by combining a λ/2 retardation plate is also known (japanese patent application laid-open No. 10-90521). The λ/2 phase difference plate is also manufactured by the same material method as the λ/4 phase difference plate. The combination of the stretching type retardation plate and the liquid crystal coating type retardation plate is arbitrary, but both of them are preferable because the thickness of the film can be reduced by using the liquid crystal coating type retardation plate.

In order to improve visibility in the oblique direction of the circularly polarizing plate, a method of laminating a front C-plate is also known (japanese patent application laid-open No. 2014-224837). The positive C plate may be a liquid crystal coated retardation plate or a stretched retardation plate. The phase difference in the thickness direction of the positive C plate is-200 to-20 nm, preferably-140 to-40 nm.

(touch sensor)

The touch sensor is used as an input mechanism. As the touch sensor, various types such as a resistive film type, a surface acoustic wave type, an infrared ray type, an electromagnetic induction type, and a capacitance type have been proposed, and any type may be used. Among these, the electrostatic capacity system is preferable.

The capacitive touch sensor is divided into an active region and an inactive region located in an outer region of the active region when viewed from a display panel surface. The active area is an area corresponding to an area (display portion) on which a screen is displayed in the display panel, and is an area in which a user's touch is perceivable, and the inactive area is an area corresponding to an area (non-display portion) on which a screen is not displayed in the display device.

The touch sensor may include: a substrate having flexible properties; a sensing pattern formed in an active region of the substrate; and each sensing line formed in an inactive area of the substrate and used for connecting the sensing pattern with an external driving circuit via a pad part. As the substrate having a flexible property, a substrate formed of the same material as the transparent substrate of the window film can be used. The toughness of the substrate of the touch sensor is preferably 2000MPa% or more in terms of suppressing cracks in the touch sensor. More preferably, the toughness may be 2000MPa to 30000MPa%.

The sensing pattern may include a first pattern formed in a first direction and a second pattern formed in a second direction. The first pattern and the second pattern are arranged in different directions from each other. The first pattern and the second pattern are formed in the same layer, and in order to sense a touch location, the patterns must be electrically connected. The first pattern is formed by connecting the unit patterns to each other via a joint, and the second pattern is formed by separating the unit patterns from each other in an island shape. The sensing pattern is formed of a known transparent electrode material. Examples of the transparent electrode material include Indium Tin Oxide (ITO), indium Zinc Oxide (IZO), zinc oxide (ZnO), indium Zinc Tin Oxide (IZTO), cadmium Tin Oxide (CTO), PEDOT (poly (3, 4-ethylenedioxythiophene)), carbon Nanotubes (CNT), graphene, and a metal wire (the metal used for the metal wire is not particularly limited, and for example, silver, gold, aluminum, copper, iron, nickel, titanium, tellurium, and chromium may be used alone or in admixture of 2 or more), and these may be used alone or in admixture of 2 or more. Preferably ITO. The bridge electrode may be formed on the insulating layer with an insulating layer interposed therebetween, and the bridge electrode may be formed on the substrate, and the insulating layer and the sensing pattern may be formed thereon. The bridge electrode may be formed of the same material as the sensing pattern, or may be formed of a metal such as molybdenum, silver, aluminum, copper, palladium, gold, platinum, zinc, tin, titanium, or an alloy of 2 or more of these metals. The first pattern and the second pattern must be electrically insulated, and thus an insulating layer is formed between the sensing pattern and the bridge electrode. The insulating layer may be formed only between the junction of the first pattern and the bridge electrode, or may be formed in a layer structure covering the sensing pattern. In the latter case, the bridge electrode may be connected to the second pattern through a contact hole formed in the insulating layer. The touch sensor may further include an optical adjustment layer between the substrate and the electrode as a layer for appropriately compensating for a difference in transmittance between a patterned region where a pattern is formed and a non-patterned region where no pattern is formed, specifically, a difference in light transmittance caused by a difference in refractive index in these regions. The optical adjustment layer may contain an inorganic insulating substance or an organic insulating substance. The optical adjustment layer can be formed by applying a photocurable composition containing a photocurable organic binder and a solvent onto a substrate. The photocurable composition may further contain inorganic particles. The refractive index of the optical adjustment layer can be increased by using the inorganic particles.

The photocurable organic adhesive may include, for example, a copolymer of monomers such as an acrylate monomer, a styrene monomer, and a carboxylic acid monomer. The photocurable organic binder may be, for example, a copolymer containing repeating units different from each other, such as an epoxy group-containing repeating unit, an acrylate repeating unit, and a carboxylic acid repeating unit.

The inorganic particles may include, for example, zirconia particles, titania particles, alumina particles, and the like.

The photocurable composition may further contain various additives such as a photopolymerization initiator, a polymerizable monomer, and a curing assistant.

Each layer (window film, circularly polarizing plate, touch sensor) forming the laminate for a flexible image display device may be formed by an adhesive. As the adhesive, the above-described aqueous adhesive, active energy ray-curable adhesive, or pressure-sensitive adhesive is generally used.

(light-shielding pattern)

The light shielding pattern may be applied as at least a portion of a bezel or a housing of the flexible image display device. The wiring disposed at the edge of the flexible image display device is hidden by a light-shielding pattern and thus is difficult to be visually recognized, thereby improving the visibility of an image. The light blocking pattern may be in the form of a single layer or a plurality of layers. The color of the light-shielding pattern is not particularly limited, and may be various colors such as black, white, and metallic colors. The light-shielding pattern may be formed of a pigment for color development, and a polymer such as an acrylic resin, an ester resin, an epoxy resin, polyurethane, or a silicone resin. They may also be used alone or in a mixture of 2 or more. The light blocking pattern may be formed using various methods such as printing, lithography, inkjet, and the like. The thickness of the light-shielding pattern may be 1 μm to 100 μm, preferably 2 μm to 50 μm. Further, a shape such as an inclination may be provided in the thickness direction of the light-shielding pattern.

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

(powder)

The production method of the present invention will be described with reference to (a) and (b) of fig. 1 again.

The powder f attached to the end face E of the optical film 50 is attached to the end face by processing the end face of the laminate 100. In general, in order to obtain a laminate 100 of a desired size from the raw material of the laminate 100, the end faces of the laminate 100 are processed. Examples of machining are cutting, grinding. Here, cutting means a concept including an opening. Therefore, as described above, the end face of the laminate 100 includes not only the end face E on the outer side of the laminate 100 as shown in fig. 1 (a), but also the end face E on the inner side of the inner wall forming the hole (opening) H of the laminate 100.

Dicing refers to a process of creating a cut from the front surface to the back surface of the laminate by inserting a blade, removing a laser, or the like, whereby the approximate shape of the laminate can be made.

Cutting refers to a process of cutting a part of an end of the stacked body by bringing a cutting blade (blade) moving relatively into contact with the end to form a new end surface. The cutting includes the hole forming process as described above. The hole drilling is a process of providing a hole H at a desired position in the laminated body 100 using a drill or the like, for example, as shown in fig. 1 (b). In such hole-forming, powder f (hole-forming chips) may adhere to an inner end surface E of the inner wall forming the hole H.

The polishing refers to a step of bringing abrasive grains (which may be fixed abrasive grains or free abrasive grains) that move relatively into contact with an end face of the laminate to cut a part of the end face. Polishing also includes a process called grinding.

For example, the material of the laminate 100 is cut into a planar shape slightly larger than a desired size by a blade or a laser, and then the end face of the cut laminate is ground and/or polished, whereby the planar shape of the laminate can be set to a predetermined size, and the squareness and planarity of the end face can be improved.

The planar shape (the shape viewed from the thickness direction) of the laminate is not particularly limited. For example, a square, a rectangle, a circle, etc. may be used.

Due to these processes on the end faces of the laminate, powder of the material constituting the laminate 100 is generated, and a part thereof adheres to the end face E of the laminate 100. Therefore, performing these processes on the laminate is one embodiment of the preparation step in the manufacturing method of the present invention. The end face E may be a face connecting 2 main faces of the laminate 100.

The average particle diameter of the powder may be, for example, 10 to 3000. Mu.m. The particle diameter is D50 of the particle size distribution on a weight basis based on the laser diffraction method.

(impact step (powder removal step by impact with Dry Ice particles))

Next, the dry ice particles are made to strike the end face E of the laminate 100 to remove the powder f on the end face from the end face.

Specifically, it is preferable that the dry ice particles are transported by gas and are caused to strike the end face E of the laminate 100.

The average particle diameter of the dry ice particles to be impacted is not particularly limited, but is preferably 100 μm or more from the viewpoint of efficiently removing the powder. Further, from the viewpoint of suppressing the adhesive layer from being damaged by dry ice impact, it is preferably 1000 μm or less.

The average particle size of the dry ice particles can be determined by a laser doppler velocimeter.

The speed of the dry ice particles to be impacted may be set to 5 m/sec to 100 m/sec.

The transport gas of the dry ice is not particularly limited, and may be, for example, nitrogen, air, or carbon dioxide.

Specifically, a dry ice particle supply unit (device) 300 as shown in fig. 3 may be used.

The device is provided with: 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 in the line L1, and a valve 360 is provided in the line L2.

The valve 340 is opened to adiabatically expand the liquid from the liquid carbon dioxide source 310 at the orifice 350 to produce dry ice particles (dry ice snow) which are delivered to the nozzle 320. The valve 360 is opened, gas is supplied from the carrier gas source 330 to the nozzle 320, and the dry ice particles d are ejected from the nozzle 320 by the gas and supplied to the end face E of the stacked body 100.

The particle diameter of the dry ice particles d can be adjusted by the distance (adiabatic expansion distance) after adiabatic expansion of the orifice 350 until the dry ice particles are ejected from the nozzle 320, or the distance (ejection distance) between the nozzle 320 and the target to which the dry ice particles are supplied. Further, an appropriate preliminary experiment using a dry ice particle supply unit (device) may be performed to confirm the degree of removal of the powder f and adjust the adiabatic expansion distance and the ejection distance.

It is preferable that the distance (ejection distance) between the nozzle 320 and the end face E of the laminate 100 is less than 20 mm. The adiabatic expansion distance may be set to 10 to 500mm, for example.

It is preferable that the conveying unit 400 relatively moves the positions of the laminate 100 and the nozzle 320 so that the portion on which the dry ice particles d impinge is scanned on the end face E. For example, in fig. 3, the conveying section 400 may be used to scan the laminate 100 in a plane orthogonal to the ejection direction (lateral direction) of the dry ice particles d so as to move the impact portion of the dry ice particles d on the end face E.

The scanning speed of the impact portion of the dry ice particles d on the end face E may be set to 1 to 100 m/sec.

(action)

According to the present embodiment, since the dry ice particles d are blasted to the end face E of the laminated body 100, powder such as cutting chips, drilling chips, and polishing chips is appropriately removed from the end face. This is preferable because contamination by the powder is reduced in the subsequent step. Further, the time required for removing the powder is shorter than that of methods such as attaching and detaching a tape.

Further, the particle size of the dry ice particles to be impacted is preferably from 100 to 1000 μm, because the powder removal rate can be improved and the loss of the adhesive layer at the end face can be suppressed, and more preferably from 200 to 700 μm.

(removal of powder from a laminated Structure comprising a plurality of laminated bodies)

In the above, the dry ice particles are applied to one laminate 100, but as shown in fig. 4, dry ice is applied to an end face E of a laminated structure 120 in which a plurality of laminates 100 are laminated in the thickness direction. This allows a large amount of the stack 100 to be handled.

(order of processing end face and removing powder)

After the processing (cutting, and polishing) of a part of the end face of the laminate 100 is completed, dry ice particles may be simultaneously blown to the part of the end face where the processing is completed to remove the powder while the other part of the end face of the laminate 100 is processed. This can shorten the process time.

Conversely, after all the processes such as cutting, and polishing of the end face of the laminate are completed, the end face of the laminate 100 may be impacted with dry ice particles to clean the powder of the end face, and when the end face is impacted with dry ice particles, the other portions of the end face of the laminate may not be processed. In this case, since the atmosphere (space) in which the powder is removed by the impact of the dry ice particles and the atmosphere (space) in which the end face is processed can be distinguished, the end face contamination by the powder generated by the processing can be prevented.

(atmosphere in the impact step (powder removal step))

In the case of using the ice particles in the step of removing the powder from the end surfaces of the laminate and the laminate structure, the atmosphere surrounding the laminate and the laminate structure may be an air atmosphere, but an atmosphere of nitrogen, carbon dioxide, or the like may be used as necessary. The temperature of the atmosphere is usually 20 to 30 ℃ and preferably 20 to 27 ℃. The relative humidity of the atmosphere is generally less than 80%, preferably 30 to 75%, more preferably 40 to 70%. When the relative humidity of the atmosphere is 80% or more, condensation occurs due to cooling of the laminate or the laminated structure, and a film having high water absorption (for example, a polarizing plate) or the like in the laminate absorbs water and swells, and the like, and thus, the appearance and optical characteristics of the laminate or the laminated structure may be deteriorated.

(apparatus for producing optical Member)

Next, an apparatus 1000 for manufacturing an optical member suitable for carrying out the above method will be described with reference to fig. 5.

The manufacturing apparatus 1000 includes: an end face processing portion 200 for cutting, or polishing an end face of the laminated body 100 or the laminated structure 120; a dry ice particle supply unit 300 for impacting dry ice particles on a portion of the laminated body 100 that is to be processed into the end face processing unit 200; and a conveying section 400 for conveying the laminate 100.

In fig. 5, a cutting device is drawn as the end face machining portion 200. The cutting device is provided with: a rotating shaft 210 extending in a horizontal direction, a disc 220 attached to the rotating shaft, and a cutter blade 230 attached to the disc 220. By the rotation of the cutting blade 230, the end face of the laminate or the like can be cut.

For convenience, only the nozzle 320 is described in the dry ice particle supply unit 300.

The conveying section 400 includes: a pair of upper and

lower jigs

420 and 422 for sandwiching and supporting the stacked body 100 or stacked structure 120 in the thickness direction; a column 430 for pressing the upper jig 420 in the thickness direction (downward direction); a rotating mechanism 410 connected to the lower jig 422 to rotate the upper jig 420 and the lower jig 422 around a vertical axis (Z axis); and a moving mechanism 440 for moving the upper jig 420 and the lower jig 422 in the horizontal direction (X direction).

Next, a method for manufacturing an optical member using the apparatus will be described. First, the laminate 100 or the laminate structure 120 is sandwiched between the upper jig 420 and the lower jig 422. Next, the upper jig 420 is pressed toward the lower jig 422 by the column 430, thereby fixing the stacked body 100 or the stacked structural body 120. In the present embodiment, the stacked body 100 or the stacked structure 120 has a rectangular shape as viewed from above and has 4 end faces. Therefore, the rotation position of the stacked body 100 or the stacked structure 120 is adjusted by the rotation mechanism 410 so that the 2 end faces E are directed parallel to the X axis.

Next, the end face machining portion 200 is started. Specifically, the disk 220 is rotated. Next, the moving mechanism 440 moves the stacked body 100 and the stacked structure 120 in the X direction to bring the cutting blade 230 of the end-face machined portion 200 into contact with the end face E. Thereby, the pair of end faces E of the stacked body 100 and the stacked structure 120 facing each other are cut by the cutting blade 230. At this time, chips adhere to the end surface E.

Next, the stacked body 100 and the stacked structure 120 are moved in the-X direction by the conveying unit 400, and the dry ice particles are supplied from the nozzle 320 of the dry ice particle supply unit 300. As a result, the cut end surfaces E of the laminated body 100 and the laminated structure 120 are impacted with dry ice particles, and the powder on the end surfaces E is removed.

Next, the stacked body 100 and the stacked structure 120 are further moved in one direction by the conveying unit 400, and the stacked body 100 and the stacked structure 120 are rotated by the rotating mechanism 410 so that the remaining 2 end faces are parallel to the X direction. Then, as in the case of the above, the processing of the remaining 2 end faces and the subsequent powder removal by the dry ice particles may be performed in this order.

The end surface processing portion 200 may be provided in various forms according to the processing method. For example, as shown in fig. 6, cutting can be performed by a CANNA type rotary blade having a cylindrical body 240 rotating around a vertical axis and a long blade 250 provided so as to extend in an axial direction on an outer peripheral surface of the cylindrical body 240.

In addition, a polishing plate having a large number of abrasive grains on the surface of the disk may be used instead of the cutting blade 230 to perform polishing.

When cutting and polishing are not necessary, a cutting device may be used.

Finally, an example of a method of removing the powder f (drilling debris) adhering to the end face E of the hole H provided in the laminate 100 will be described with reference to fig. 7.

First, the laminated body 100 is subjected to hole-drilling, and a plurality of laminated bodies 100 are prepared in which the powder (drilling chips) f adhere to the inner end surfaces E of the holes H. As shown in fig. 1 (b), each laminate 100 has a hole H provided at a predetermined position by drilling. Next, the stacked bodies 100 are stacked such that the positions of the holes H of the respective stacked bodies 100 are aligned on one axis (axis extending in the thickness direction), thereby obtaining a stacked structure 120. Thus, the holes H of the laminated laminates 100 are connected to each other, and through holes H' penetrating in the thickness direction of the laminate 120 are formed in the laminate 120.

Of the pair of upper jig 420 and lower jig 422 pressing the laminated structure 120 in the thickness direction, one jig is provided with a dry ice particle supply port 420a in advance, and the other jig is provided with a dry ice particle recovery port 422b in advance. The upper jig 420 and the lower jig 422 are disposed so that the through-hole H' communicates with the dry ice particle supply port 420a and the ice particle recovery port 422b, and the stacked structure 120 is pressed in the thickness direction. This completes the preparatory process before the dry ice impact process.

Next, dry ice particles are supplied from the nozzle 320 into the through hole H' through the dry ice particle supply port 420a (impact step). The dry ice particles ejected from the nozzle 320 spread in the width direction as they advance, impact the end face E of the through hole H' of the laminated structure 120, and are discharged from the dry ice particle collection port 422b together with the powder f. With this apparatus, the powder f can be effectively removed from the laminate 100 in which the powder f adheres to the end face E of the inner wall of the hole H by the hole opening process.

Examples

(laminate Material)

A raw material laminate having the following layer composition was obtained: protective film (53 μm made of polyethylene terephthalate)/protective film (32 μm made of TAC (triacetyl cellulose))/polarizing plate (12 μm made of PVA (iodine adsorbing polyvinyl alcohol))/protective film (23 μm made of COP (cyclic olefin resin))/adhesive layer (acrylic adhesive: 20 μm)/release film (PET: 38 μm).

The protective film and the polarizing plate are bonded together by an aqueous adhesive. The thickness of the laminate was 178 μm.

(processing of end face of laminate)

The raw material laminate was cut into a rectangular shape having a size of 140 × 65mm with a thomson blade to obtain a laminate.

Next, the 50-piece stacked body was stacked to obtain a stacked structure. Each end face of the laminated structure is cut by a cutting device. Then, each end face of the laminated structure is polished by a polishing apparatus.

(removal of powder on end face of laminate)

In each of the examples and comparative examples, the removal of the powder on the end face of the laminate was performed under the following conditions.

(example 1)

Dry ice particle supply device: carbon dioxide dry ice blasting

CO ₂ Pressure: 5MPa (note that, CO is ₂ Pressure means supply pressure to the orifice)

Air pressure: 0.5Mpa

Distance between the front end of the nozzle and the end face: about 50mm

Scanning speed of the nozzle: 50mm/5 sec

Center position of nozzle and nozzle scanning direction: the nozzle is directed toward the center in the thickness direction of the end face of the laminated structure, and the nozzle is scanned in the direction perpendicular to the thickness of the end face of the laminated structure.

Average particle diameter of dry ice particles: 1 to 100 mu m

Atmosphere temperature: 24 ℃ to 26 ℃ and relative humidity of the atmosphere: 45 to 65 percent of

(example 2)

Dry ice particle supply device: carbon dioxide dry ice blasting

CO ₂ Pressure: 7Mpa

Air pressure: 0.5Mpa

Distance between the front end of the nozzle and the end face: about 50mm

Scanning speed of the nozzle: 50mm/5 sec

Average particle diameter of dry ice particles: 200 to 700 mu m or less

(example 3)

Dry ice particle supply device: pellet dry ice blasting

Particle diameter: phi 3mm

Air pressure: 0.5Mpa

Distance between nozzle tip and end face: about 50mm

Scanning speed of the nozzle: 50mm/5 sec

Average particle diameter of dry ice particles: over 1000 μm

(example 4)

The removal of the powder on the end face of the laminate was performed under the same conditions as in example 2, except that the atmospheric temperature was 26 ℃ and the relative humidity of the atmosphere was 80 to 90%.

The laminate was cooled by contact with the dry ice particles at the time of removal, and condensation occurred in the laminate. When the dew condensation portion was observed, the polishing debris and the defect were not generated, but swelling occurred at the end of the laminate.

Comparative example 1

The end face of the laminated structure was wiped with a clean room wiper (KURARAY KURAFLEX) impregnated with ethanol.

Comparative example 2

The OLFA dicing blade is moved along the end face of the laminated structure.

Comparative example 3

An adhesive tape (Cellotape (registered trademark) manufactured by Nichiban) was attached to an end face of the laminated structure, and then the adhesive tape was peeled off from the end face.

Comparative example 4

An air stream was blown to the end face 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 powder remaining on the end face and the presence or absence of defects in the adhesive layer on the end face.

The results are shown in Table 1.

[ Table 1]

Note that "end surface powder remains" indicates that no powder is observed in a 30mm long (hereinafter simply referred to as "length") visual field perpendicular to the thickness, Δ indicates that 1 to 2 powders are observed in a 30mm long visual field, and × "indicates that 3 or more powders are observed in a 30mm long visual field.

The circle of "adhesive layer defect on the end face" indicates that no defect was observed in a 30 mm-long (hereinafter, simply referred to as "length") visual field in the direction perpendicular to the thickness, the triangle indicates that 1 to 2 defects were observed in a 30 mm-long visual field, and the x indicates that 3 or more defects were observed in a 30 mm-long visual field.

Description of the reference numerals

50 method 8230, an optical film 80 method 8230, an adhesive layer 100 method 8230, a laminated body 120 method 8230, a laminated structure 200 method 8230, an end face processing part 300 method 8230, a dry ice particle supply part 400 method 8230, a conveying part 1000 method 8230, a manufacturing device of an optical member f method 8230, powder E8230and an end face.

Claims

1. A method of manufacturing an optical member, comprising:

preparing a laminate having an optical film and a pressure-sensitive adhesive layer provided on one surface of the optical film, and having powder adhered to an end surface thereof; and

a step of removing the powder from the end face of the laminate by causing dry ice particles to strike the end face,

the laminate has a hole penetrating in the thickness direction of the optical film and the adhesive layer,

the end surface is an inner wall of the hole.

2. The method according to claim 1, wherein the dry ice particles have an average particle size of 100 to 1000 μ ι η.

3. The method according to claim 1 or 2, wherein in the impacting step, the dry ice particles are impacted against an end face of a laminated structure in which a plurality of the laminates are laminated.

4. The method according to claim 1 or 2, wherein the dry ice particles are caused to impact a portion of the end face while at least one selected from the group consisting of cutting, and grinding is performed on other portions of the end face of the laminate.

5. The method according to claim 1 or 2, wherein in the preparation step, the end face is subjected to at least one treatment selected from the group consisting of cutting, chipping, and grinding, and when the dry ice particles are caused to strike a part of the end face, the end face is not subjected to any one treatment selected from the group.

6. The method according to claim 1 or 2, wherein the optical film is at least one selected from the group consisting of a polarizing plate, a protective film, a phase difference film, a brightness enhancement film, a window film, and a touch sensor; a laminated film containing 2 or more of at least 1 kind selected from the group, or a laminated film containing at least 2 kinds selected from the group.

7. The method according to claim 1 or 2, wherein the relative humidity of the atmosphere in the step of causing the dry ice particles to strike the end face is 30% to 75%.

8. An optical member manufacturing apparatus, comprising:

an end face processing unit for cutting, cutting or polishing an end face of a laminate having an optical film and a pressure-sensitive adhesive layer provided on one surface of the optical film; and

a dry ice particle supply unit for causing dry ice particles to strike a portion of the laminate body which is to be processed into the end face processed portion,

the end surface is an inner wall of the hole.

9. The apparatus for manufacturing an optical member according to claim 8, further comprising: and a conveying unit that moves the laminate between the end surface processing unit and the dry ice particle supply unit.