CN106957610B

CN106957610B - Spacer-attached adhesive layer, spacer-attached optical film, image display device, and methods for manufacturing spacer-attached adhesive layer and image display device

Info

Publication number: CN106957610B
Application number: CN201610862579.1A
Authority: CN
Inventors: 森本有; 外山雄祐; 石井孝证
Original assignee: Nitto Denko Corp
Current assignee: Nitto Denko Corp
Priority date: 2015-09-30
Filing date: 2016-09-28
Publication date: 2021-08-06
Anticipated expiration: 2036-09-28
Also published as: KR20170038700A; TWI716461B; JP2017066271A; KR102575111B1; JP6208728B2; CN106957610A; TW201726854A

Abstract

The invention provides an adhesive layer with a spacer, which can prevent the defect of a liquid crystal panel caused by uneven brightness caused by bright spots by preventing oligomer contained in a base material film such as a polyester film used in the spacer from dissolving into the adhesive layer, can prevent the uneven white color of the liquid crystal panel even if an RTP attaching process is applied in the manufacture of a liquid crystal display device, and also provides an optical film with the adhesive layer with the spacer. The spacer-provided adhesive layer has an adhesive layer on a spacer, the spacer has a release layer on a base film, and has an oligomer prevention layer and a conductive layer between the base film and the release layer, and the adhesive layer is provided on the release layer of the spacer.

Description

Spacer-attached adhesive layer, spacer-attached optical film, image display device, and methods for manufacturing spacer-attached adhesive layer and image display device

Technical Field

The present invention relates to an adhesive layer with a spacer and an optical film with an adhesive layer with a spacer. The present invention relates to an image display device in which the pressure-sensitive adhesive layer side of an optical film with a pressure-sensitive adhesive layer is bonded to a display panel in a state in which a spacer is peeled from the optical film with a spacer, and a method for manufacturing the same.

As the optical film, surface treatment films such as a polarizing film, a retardation plate, an optical compensation film, a brightness enhancement film, and an antireflection film, and films obtained by laminating these films can be used. The optical film with a pressure-sensitive adhesive layer obtained by peeling the spacer from the optical film with a pressure-sensitive adhesive layer with a spacer is used in image display devices such as liquid crystal display devices, organic EL display devices, CRTs, PDPs, and the like.

Background

In an image display device such as a liquid crystal display device, an optical film such as a polarizing film is used. When the optical film is bonded to a display panel such as a liquid crystal panel, an adhesive is generally used. Since there is an advantage that a drying step for bonding the optical film is not necessary, an optical film with an adhesive layer is generally used in which an adhesive is provided as an adhesive layer on one side of the optical film in advance. In general, an optical film with an adhesive layer is manufactured as an optical film with a spacer-equipped adhesive layer in which a spacer (also referred to as a release film or a release liner) is provided on the surface of the adhesive layer for the purpose of protecting the adhesive layer before bonding.

In such an optical film with a spacer-equipped pressure-sensitive adhesive layer, oligomer contained in a base film such as a polyester film used for the spacer may elute into the pressure-sensitive adhesive layer, and a defect of the liquid crystal panel due to luminance unevenness or the like caused by a bright spot may occur, and therefore, patent document 1 proposes to provide an oligomer prevention layer on the spacer.

In addition, in the manufacture of a liquid crystal display device, when a spacer of an optical film with a spacer-attached pressure-sensitive adhesive layer is peeled off, static electricity (peeling electrification) is generated in the optical film with the pressure-sensitive adhesive layer and the spacer. When an optical film having an electrostatic pressure-sensitive adhesive layer is bonded to a liquid crystal panel, induced charging occurs in the liquid crystal panel. The induced charge affects the alignment of the liquid crystal panel, and causes defects such as image display unevenness. In addition, static electricity may cause problems such as product defects due to adhesion or introduction of foreign substances or the like at a manufacturing site.

Patent documents 2 to 4 propose pressure-sensitive adhesive sheets having a pressure-sensitive adhesive layer provided with an antistatic function by blending an ionic compound or a conductive polymer into the pressure-sensitive adhesive layer in order to suppress the generation of static electricity. Patent document 5 proposes a spacer in which an electrostatic interference prevention function is provided to a release layer of the spacer.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2006-113600

Patent document 2: japanese laid-open patent publication No. 6-128539

Patent document 3: japanese Kokai publication No. 2007-536427

Patent document 4: japanese patent laid-open publication No. 2003-246874

Patent document 5: japanese patent laid-open No. 2014-141557

Disclosure of Invention

Problems to be solved by the invention

However, even in the case of using the optical film with a pressure-sensitive adhesive layer with a spacer of patent document 5, the occurrence of static electricity at the time of peeling the spacer cannot be sufficiently suppressed. In particular, it was found that when a liquid crystal display device was manufactured by a step (Roll-To-panel (rtp) bonding step) of bonding the pressure-sensitive adhesive layer-carrying optical film exposed by peeling the spacer (see fig. 3) from the pressure-sensitive adhesive layer-carrying optical film while the spacer was peeled off (simultaneously with the peeling) To the liquid crystal panel, induced charging occurred by bonding the pressure-sensitive adhesive layer-carrying optical film having static electricity without attenuation To the liquid crystal panel. In the subsequent manufacturing process, the liquid crystal panel that has been induced to become charged comes into contact with a dielectric such as a manufacturing machine, thereby generating a current (magnetic field) in the liquid crystal panel, and white unevenness (light leakage) that causes the liquid crystal panel to become white due to poor alignment of the liquid crystal is generated. If white unevenness occurs in the liquid crystal panel, the white unevenness continues until the liquid crystal alignment returns to its original state, and therefore quality inspection in the manufacturing process is delayed, which causes a problem of deterioration in production efficiency.

An object of the present invention is to provide a spacer-equipped adhesive layer that can prevent the occurrence of defects in a liquid crystal panel due to luminance unevenness caused by bright spots by suppressing the elution of oligomers contained in a base film such as a polyester film used for a spacer into the adhesive layer, and can suppress white unevenness of the liquid crystal panel even when the above-described RTP bonding step is applied in the production of a liquid crystal display device, and to provide an optical film with a spacer-equipped adhesive layer.

Another object of the present invention is to provide an image display device, wherein the pressure-sensitive adhesive layer side of the optical film with a pressure-sensitive adhesive layer in a state where the spacer is peeled off from the optical film with a pressure-sensitive adhesive layer with a spacer is bonded to at least one surface of the display panel, and a method for manufacturing the image display device.

Means for solving the problems

The present inventors have made extensive studies to solve the above problems, and as a result, have found a spacer-attached pressure-sensitive adhesive layer, an optical film with a spacer-attached pressure-sensitive adhesive layer, an image display device, and a method for manufacturing the same, and have completed the present invention.

That is, the present invention relates to a spacer-attached adhesive layer having an adhesive layer on a spacer, wherein the spacer has a release layer on a base film, and has an oligomer prevention layer and a conductive layer between the base film and the release layer, and wherein the adhesive layer is provided on the release layer of the spacer.

In the spacer-equipped adhesive layer of the present invention, the oligomer prevention layer is preferably a layer formed from a composition containing a silica-based material and/or a polyvinyl alcohol-based resin.

In the spacer-equipped adhesive layer of the present invention, the conductive layer is preferably a layer formed of a conductive composition containing a conductive polymer.

In the spacer-equipped adhesive layer of the present invention, the surface resistance value of the release layer is preferably 1.0 × 10¹²Omega/□ or less.

In the spacer-equipped adhesive layer of the present invention, the adhesive layer is preferably a layer formed from an adhesive composition containing a base polymer and a conductive compound.

In the spacer-equipped adhesive layer of the present invention, the surface resistance value of the adhesive layer is preferably 1.0 × 10¹²Omega/□ or less.

The present invention relates to an optical film with a spacer-equipped pressure-sensitive adhesive layer, characterized in that the pressure-sensitive adhesive layer side of the spacer-equipped pressure-sensitive adhesive layer is bonded to at least one surface of the optical film.

The present invention relates to an image display device, wherein a pressure-sensitive adhesive layer side of an optical film with a pressure-sensitive adhesive layer is bonded to at least one surface of a display panel, the optical film with the pressure-sensitive adhesive layer being in a state in which the spacer is peeled from the optical film with the pressure-sensitive adhesive layer with a spacer.

The present invention relates to a method for manufacturing an image display device, including: a roll material preparation step of preparing a long sheet of the optical film with the spacer-attached pressure-sensitive adhesive layer as a roll material; a display panel conveyance preparation step of conveying the display panel to a bonding position for preparation; and a bonding step of bonding the pressure-sensitive adhesive layer-attached optical film exposed by peeling the spacer to the display panel conveyed to the bonding position while the spacer is peeled off from the optical film with the spacer-attached pressure-sensitive adhesive layer by a peeling member by pulling out the optical film with the spacer from the roll.

Effects of the invention

The spacer-equipped adhesive layer has a structure in which an oligomer prevention layer and a conductive layer are laminated between a base film of a spacer and a release layer. The oligomer prevention layer can suppress elution of oligomers contained in a base film such as a polyester film of the spacer to the adhesive layer, and is useful for preventing defects of the liquid crystal panel such as luminance unevenness due to bright spots.

In the optical film with a pressure-sensitive adhesive layer with a spacer according to the present invention, which is obtained by bonding the pressure-sensitive adhesive layer with a spacer to the optical film on the pressure-sensitive adhesive layer side, the spacer has the conductive layer, and therefore, generation of static electricity is small when the spacer is peeled off. On the other hand, if a conductive agent such as a conductive compound is added to the oligomer prevention layer and the release layer, the conductive agent in the oligomer prevention layer and the release layer interacts with the conductive adhesive, and the electrostatic interference prevention function may be impaired.

In addition, in the optical film with a spacer-attached pressure-sensitive adhesive layer according to the present invention, when the liquid crystal display device is manufactured, even when a step (RTP bonding step) is applied in which the spacer is peeled off from the optical film with a spacer-attached pressure-sensitive adhesive layer by a peeling member (simultaneously with the peeling), and the pressure-sensitive adhesive layer side of the optical film with a pressure-sensitive adhesive layer exposed after the peeling of the spacer is bonded to the liquid crystal panel, the spacer has a conductive layer, and therefore, generation of static electricity (peeling electrification) can be suppressed.

Drawings

Fig. 1 is a schematic cross-sectional view showing an example of the structure of an adhesive layer with a spacer.

Fig. 2 is a schematic cross-sectional view showing an example of the structure of an optical film with a spacer-attached pressure-sensitive adhesive layer.

Fig. 3 is a schematic diagram illustrating an RTP bonding step in the method for manufacturing an image display device.

Detailed Description

Hereinafter, embodiments of the present invention will be described in detail.

< integral Structure of spacer-attached adhesive layer and optical film with spacer-attached adhesive layer >

Fig. 1(a) and (b) schematically show typical configurations of the spacer-equipped adhesive layer of the present invention. The spacer-attached adhesive layer 2 is in a form in which an adhesive layer 21 is provided on the release layer 12 of the spacer 1. The spacer 1 is provided with an oligomer prevention layer 13 and a conductive layer 14 between the base film 11 and the release layer 12. The order of lamination of the oligomer prevention layer 13 and the conductive layer 14 is not limited, but in the case of (a), since the oligomer prevention layer 13 is in contact with the base film 11, the effect of suppressing elution of the oligomer contained in the base such as a polyester film into the adhesive layer is high, and since the conductive layer 14 is in contact with the release layer 12, the effect of suppressing white unevenness of the liquid crystal panel is high. In the case of (b), the effect of suppressing elution of the oligomer into the adhesive layer while maintaining the electrostatic interference prevention effect of the entire spacer 1 is high. The oligomer prevention layer 13 and the conductive layer 14 may be stacked in a multilayer structure including the oligomer prevention layer 13 and the conductive layer 14.

Fig. 2 schematically shows a typical configuration of the optical film with a spacer-attached pressure-sensitive adhesive layer of the present invention. The optical film 3 with a spacer-attached pressure-sensitive adhesive layer is formed by bonding an optical film 31 to the spacer-attached pressure-sensitive adhesive layer 2. The optical film 4 with a pressure-sensitive adhesive layer, in which the spacer 1 is peeled from the optical film 3 with a pressure-sensitive adhesive layer with a spacer, is used by attaching the pressure-sensitive adhesive layer 21 to a display panel as an adherend.

< adhesive layer with spacer >

The spacer-equipped adhesive layer of the present invention has a structure in which the adhesive layer is provided on the spacer. The spacer has an oligomer prevention layer and a conductive layer between the base material film and the release layer.

< substrate film >

As the base film of the spacer of the present invention, a plastic film can be used. Examples of the plastic film include polyolefin films such as polyethylene film, polypropylene film, polybutylene film, polybutadiene film, and polymethylpentene film, and vinyl chloride films such as polyvinyl chloride film and vinyl chloride copolymer film; polyester films such as polyethylene terephthalate films, polybutylene terephthalate films, and polynaphthalene terephthalate films; and polyurethane films, ethylene-vinyl acetate copolymer films, and the like. In the present invention, for the purpose of preventing elution of the oligomer in the base film, a polyester film is preferably used as the base film.

The thickness of the base material film is usually 5 to 200 μm, preferably 5 to 100 μm. In forming the oligomer prevention layer and the conductive layer, the base material film may be subjected to surface treatment such as corona treatment or plasma treatment in advance.

< oligomer prevention layer >

The oligomer prevention layer of the present invention can be formed using an appropriate material for preventing oligomers contained in a base film such as a polyester film from eluting into the pressure-sensitive adhesive layer. As a material for forming the oligomer prevention layer, an inorganic substance, an organic substance, or a composite material thereof can be used. Examples of the inorganic substance include a silica-based material, a metal containing gold, silver, platinum, palladium, copper, aluminum, nickel, chromium, titanium, iron, cobalt, tin, an alloy thereof, or the like, a metal oxide containing indium oxide, tin oxide, titanium oxide, cadmium oxide, or a mixture thereof, and another metal compound containing steel iodide, or the like. Examples of the organic substance include polyvinyl alcohol-based resins, acrylic resins, urethane-based resins, melamine-based resins, UV-curable resins, and epoxy-based resins. Further, as the composite material, a mixture of the above organic substance and inorganic particles such as alumina, silica, mica and the like can be given.

The oligomer prevention layer is preferably formed of a composition containing a silica-based material and a polyvinyl alcohol-based resin.

< silica-based Material >

Examples of the silica-based material include organosiloxanes represented by the following general formula (I).

[ solution 1]

In the general formula (I), R¹And R²Each independently is an epoxy group-containing organic group such as γ -glycidoxypropyl group, 3, 4-epoxycyclohexylethyl group or an alkoxy group such as methoxy group or ethoxy group, R³An alkoxy group such as a methoxy group or an ethoxy group, or a group represented by the following general formula (II). n and m are integers of 0 to 10.

[ solution 2]

In the general formula (II), R⁴Is with R¹Radical or R²The same organic group or alkoxy group containing an epoxy group.

Specific examples of the organosiloxane include monomers such as γ -glycidoxypropyltrimethoxysilane, 2- (3, 4-epoxycyclohexyl) ethyltrimethoxysilane, 2- (3, 4-epoxycyclohexyl) ethyltriethoxysilane, 5, 6-epoxycyclohexyltriethoxysilane, and tetraethoxysilane, and hydrolysis products (oligomers) of these monomers or a mixture of these monomers.

Further, examples of the silica-based material include silane compounds having an amino group. The silane compound having an amino group is preferably an alkoxysilane represented by the following general formula (III).

Y－R－Si－(X)₃……(III)

In the general formula (III), Y represents an amino group, R represents an alkylene group such as a methylene group, an ethylene group or a propylene group, X represents an alkoxy group such as a methoxy group or an ethoxy group, an alkyl group or an organic functional group having these groups, and at least 1 or more of these groups are alkoxy groups.

Specific examples of the silane compound having an amino group include N- β (aminoethyl) γ -aminopropyltrimethoxysilane, N- β (aminoethyl) γ -aminopropyltriethoxysilane, N- β (aminoethyl) γ -aminopropylmethyldimethoxysilane, γ -aminopropyltrimethoxysilane, and N-phenyl- γ -aminopropyltrimethoxysilane.

Examples of the silica-based material include (meth) acryloyl group-containing silane compounds such as 3-acryloyloxypropyltrimethoxysilane and 3-methacryloyloxypropyltriethoxysilane, and isocyanate group-containing silane compounds such as 3-isocyanatopropyltriethoxysilane.

Specific examples of the silica-based material include KR-401N, X-40-9227, X-40-9247, KR-510, KR-9218, KR-213, KR-217, X-41-1053, X-40-1056, X-41-1805, X-41-1810, X-40-2651, X-40-2652B, X-40-2655A, X-40-2761, and X-40-2672 manufactured by shin-Etsu chemical industries, Ltd.

The silica-based material may be used in only 1 kind, or 2 or more kinds.

The oligomer prevention layer formed of the silica-based material may contain an organic compound having a metal element (a metal compound such as a metal chelate), a catalyst, and the like, as necessary. The metal organic compound having a metal element may be used in only 1 kind, or may be used in 2 or more kinds.

Among the metal organic compounds having a metal element, organic compounds having an aluminum element, organic compounds having a titanium element, and organic compounds having a zirconium element, which have a chelate structure, are preferable, in particular, from the viewpoint of excellent oligomer elution prevention performance. This compound is described in detail in "handbook of crosslinking agent" (Hill. jin III, Kao, 2 years edition by Dacheng corporation, Ohio).

The oligomer prevention layer formed using the silica-based material can be formed by dissolving the silica-based material in a solvent such as alcohol, applying the obtained solution to a substrate film or a conductive layer, and drying the applied solution. The concentration of the solution in which the silica-based material is dissolved is not particularly limited, but is preferably about 0.1 to 40 wt%. The drying temperature after coating is not particularly limited, but is preferably about 100 to 150 ℃. The drying time after coating is not particularly limited, but is preferably about 30 seconds to 30 minutes.

< composition containing polyvinyl alcohol resin >

Examples of the polyvinyl alcohol resin include polyvinyl alcohol and derivatives thereof. Examples of the derivative of polyvinyl alcohol include polyvinyl formal, polyvinyl acetal, and resins modified with an olefin such as ethylene or propylene, an unsaturated carboxylic acid such as acrylic acid, methacrylic acid, crotonic acid, an alkyl ester thereof, acrylamide, and the like. The polyvinyl alcohol resin may be used in only 1 kind, or 2 or more kinds.

The polymerization degree of the polyvinyl alcohol resin is not particularly limited, but a resin of 100 or more, preferably 300 to 40000, is usually suitably used. On the other hand, the saponification degree of the polyvinyl alcohol resin is not particularly limited, but a resin of 70 mol% or more, preferably 80 mol% or more, and 99.9 mol% or less is suitably used.

The composition containing the polyvinyl alcohol resin may contain a binder polymer. Examples of the binder polymer include polyacrylamide, polyalkylene glycol, polyalkyleneimine, methyl cellulose, hydroxy cellulose, starches, polyurethane, polyester, polyacrylate, chlorine-based polymer (polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, etc.), polyolefin, and the like. Among them, when the oligomer-preventing layer is applied by a coating and stretching method, there may be mentioned organic polymers which can be used as nonionic, cationic or amphoteric aqueous solutions or aqueous dispersions, and among them, when polyurethane, polyester or polyacrylate is used, the adhesiveness is good. Hydrophilic properties can be imparted by copolymerizing a nonionic, cationic or amphoteric hydrophilic component as one component of the monomers of these polymers, and the resultant polymer can be dispersed in water.

The composition containing the polyvinyl alcohol resin may contain a crosslinking agent. Examples of the crosslinking agent include methylolated or hydroxyalkylated urea-based, melamine-based, guanamine-based, acrylamide-based, polyamide-based compounds, epoxy compounds, aziridine compounds, blocked polyisocyanates, silane coupling agents, titanium coupling agents, aluminum zirconium coupling agents, and the like. These crosslinking components may also be prebonded with the binder polymer.

The composition containing the polyvinyl alcohol resin may contain inorganic particles for the purpose of improving the adhesion of the oligomer-preventing layer and the sliding property. Examples of the inorganic particles include silica, alumina, kaolin, calcium carbonate, titanium oxide, and barium salt.

The formation of the oligomer-preventing layer can be carried out by dissolving the composition containing the polyvinyl alcohol resin in a solvent such as water or alcohol, applying the obtained solution to a substrate film or an oligomer-preventing layer, and then drying the applied solution. Further, the sheet may be stretched during drying. The concentration of the solution in which the composition containing the polyvinyl alcohol resin is dissolved is not particularly limited, but is preferably about 0.1 to 40 wt%. The drying temperature after coating is not particularly limited, but is preferably about 60 to 200 ℃. The drying time after coating is not particularly limited, but is preferably about 3 to 60 seconds. If necessary, a combination of heat treatment and irradiation with active energy rays such as ultraviolet irradiation may be used.

The content of the polyvinyl alcohol resin in the oligomer prevention layer is not particularly limited, but is preferably 10 to 100 wt%, more preferably 20 to 90 wt%, and most preferably 30 to 80 wt%.

The method for forming the oligomer prevention layer is not particularly limited as long as it is appropriately selected according to the material for forming the oligomer prevention layer, and a coating method, a spray method, a spin coating method, an in-line coating method, or the like can be used. Further, a vacuum deposition method, a sputtering method, an ion plating method, a spray pyrolysis method, an electroless plating method, an electroplating method, or the like may be used.

The thickness of the oligomer prevention layer is preferably set to be appropriately in the range of 5 to 100nm, and more preferably 10 to 70 nm.

< conductive layer >

The conductive layer of the present invention can suppress generation of static electricity due to peeling of the spacer, and even if static electricity is generated due to peeling of the spacer, since the charge of the static electricity generated in the optical film with the pressure-sensitive adhesive layer can be rapidly transferred to the peeled spacer, it is possible to prevent white unevenness of the liquid crystal panel. The conductive layer is not particularly limited as long as it is a layer having conductivity, and examples thereof include a layer formed using a conductive composition containing a conductive polymer, a conductive composition containing a plasma surfactant such as an anionic surfactant and a cationic surfactant, a conductive composition containing a metal oxide such as tin oxide, antimony oxide, indium oxide, or zinc oxide, and the like. The conductive layer is preferably a layer formed using a conductive composition containing a conductive polymer, from the viewpoint of easily obtaining a spacer having a desired surface resistance value of the release layer.

Examples of the conductive polymer include polyaniline, polypyrrole, polythiophene, poly (ethylenedioxythiophene) (abbreviated as PEDOT), poly (ethylenedioxythiophene)/polystyrene sulfonic acid (abbreviated as PEDOT/PSS), and the like. From the viewpoint of antistatic properties and transparency, poly (ethylenedioxythiophene)/polystyrene sulfonic acid (abbreviated as PEDOT/PSS) is particularly preferred. The conductive polymer may be used in only 1 kind, or may be used in 2 or more kinds.

The conductive composition containing the conductive polymer may contain a binder resin. Examples of the binder resin include polyvinyl alcohol resins, polyester resins, polyurethane resins, acrylic resins, vinyl resins, epoxy resins, and amide resins.

The weight ratio of the conductive polymer to the binder resin (conductive polymer: binder resin) is preferably 50: 1-1: 1, more preferably 20: 1-2: 1, more preferably 15: 1-5: 1.

the conductive layer can be formed by dissolving a conductive composition containing the conductive polymer in a solvent such as water or alcohol, applying the resulting solution to a substrate film or an oligomer-preventing layer, and drying the applied solution. The concentration of the solution in which the conductive composition containing the conductive polymer is dissolved is not particularly limited, but is preferably about 0.1 to 40% by weight. The drying temperature after coating is not particularly limited, but is preferably about 100 to 150 ℃. The drying time after coating is not particularly limited, but is preferably about 1 to 60 minutes.

The method for forming the conductive layer is not particularly limited, and a coating method, a spraying method, a spin coating method, an in-line coating method, or the like can be used.

The thickness of the conductive layer is preferably 1nm to 500nm, more preferably 10nm to 200nm, and still more preferably 20nm to 100 nm.

< Release layer >

Next, a release layer is provided on the oligomer prevention layer and the conductive layer of the present invention. The release layer is provided to improve releasability from the adhesive layer. The material for forming the release layer is not particularly limited, and examples thereof include silicone-based, fluorine-based, long-chain alkyl-based, and fatty acid amide-based release agents. Among them, silicone-based release agents are preferable. The release layer may be formed as a coating layer on the oligomer prevention layer and the conductive layer. The release layer may be formed by transfer.

The silicone release agent may be, for example, an addition reaction type silicone resin. Examples of the addition reaction type Silicone resin include KS-774, KS-775, KS-778, KS-779H, KS-847H, KS-847T manufactured by shin-Etsu chemical industry, TPR-6700, TPR-6710, TPR-6721, SD7220 and SD7226 manufactured by Dow Corning Toray.

The amount of the silicone-based release layer applied (after drying) is preferably 0.01 to 2g/m²More preferably 0.01 to 1g/m²More preferably 0.01 to 0.5g/m²The range of (1).

The release layer can be formed by, for example, applying the above-mentioned material to the functional layer by a conventionally known coating method such as a reverse gravure coating method, a bar coating method, or a die coating method, and then curing the material by heat treatment at about 120 to 200 ℃ for about 30 seconds to 30 minutes. Further, heat treatment and irradiation with active energy rays such as ultraviolet irradiation may be used in combination as necessary.

The thickness of the demolding layer is usually 10-2000 nm, preferably 10-1000 nm, and more preferably 10-500 nm.

The surface resistance value of the release layer is preferably 1.0 × 10 from the viewpoint of imparting conductivity to the spacer and suppressing white unevenness of the liquid crystal panel¹²Omega/□ or less, more preferably 1.0X 10¹¹Omega/□ or less, more preferably 1.0X 10¹⁰Omega/□ or less.

< adhesive layer >

The adhesive layer of the present invention is formed from an adhesive composition. Examples of the adhesive composition include a rubber-based adhesive composition, an acrylic-based adhesive composition, a silicone-based adhesive composition, a urethane-based adhesive composition, a vinyl alkyl ether-based adhesive composition, a polyvinyl alcohol-based adhesive composition, a polyvinyl pyrrolidone-based adhesive composition, a polyacrylamide-based adhesive composition, and a cellulose-based adhesive composition. In the adhesive composition, a base polymer is preferably contained.

< basic Polymer >

Base polymer the adhesive base polymer may be selected according to the kind of the adhesive composition.

Among the above-mentioned pressure-sensitive adhesive compositions, acrylic pressure-sensitive adhesive compositions are preferably used in view of excellent optical transparency, excellent adhesive properties such as appropriate wettability, cohesiveness and adhesiveness, and excellent weather resistance and heat resistance. The acrylic adhesive composition preferably contains a (meth) acrylic polymer as an adhesive base polymer. The (meth) acrylic polymer is usually contained as a monomer unit, and contains an alkyl (meth) acrylate as a main component. The term (meth) acrylate refers to acrylate and/or methacrylate, and the term (meth) in the present invention means the same.

Examples of the alkyl (meth) acrylate constituting the main skeleton of the (meth) acrylic polymer include alkyl (meth) acrylates having 1 to 18 carbon atoms and having a linear or branched alkyl group. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a pentyl group, a hexyl group, a cyclohexyl group, a heptyl group, a 2-ethylhexyl group, an isooctyl group, a nonyl group, a decyl group, an isodecyl group, a dodecyl group, an isomyristyl group, a lauryl group, a tridecyl group, a pentadecyl group, a hexadecyl group, a heptadecyl group, and an octadecyl group. The alkyl (meth) acrylate may be used in only 1 kind, or may be used in 2 or more kinds. The average number of carbon atoms of these alkyl groups is preferably 3 to 9.

In addition, as the alkyl (meth) acrylate, an aromatic ring-containing alkyl (meth) acrylate such as phenoxyethyl (meth) acrylate or benzyl (meth) acrylate may be used in view of adhesion characteristics, durability, adjustment of retardation, adjustment of refractive index, and the like.

In the (meth) acrylic polymer, 1 or more kinds of comonomers having a polymerizable functional group having an unsaturated double bond such as a (meth) acryloyl group or a vinyl group can be introduced by copolymerization for the purpose of improving adhesiveness and heat resistance. Specific examples of the comonomer include: hydroxyl group-containing monomers such as 2-hydroxyethyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, 8-hydroxyoctyl (meth) acrylate, 10-hydroxydecyl (meth) acrylate, 12-hydroxylauryl (meth) acrylate, and (4-hydroxymethylcyclohexyl) methyl acrylate; carboxyl group-containing monomers such as (meth) acrylic acid, carboxyethyl (meth) acrylate, carboxypentyl (meth) acrylate, itaconic acid, maleic acid, fumaric acid, and crotonic acid; acid anhydride group-containing monomers such as maleic anhydride and itaconic anhydride; caprolactone adducts of acrylic acid; sulfonic acid group-containing monomers such as styrenesulfonic acid, allylsulfonic acid, 2- (meth) acrylamide-2-methylpropanesulfonic acid, (meth) acrylamidopropanesulfonic acid, (meth) sulfopropyl acrylate, and (meth) acryloyloxynaphthalenesulfonic acid; and phosphoric acid group-containing monomers such as 2-hydroxyethyl acryloylphosphate.

The (meth) acrylic polymer is not particularly limited as to the proportion of the comonomer in the (meth) acrylic polymer based on the alkyl (meth) acrylate as the main component in the weight ratio of all the constituent monomers, but the proportion of the comonomer is preferably about 0 to 20%, more preferably about 0.1 to 15%, and still more preferably about 0.1 to 10% in the weight ratio of all the constituent monomers.

The (meth) acrylic polymer is generally used in a weight average molecular weight (Mw) range of 50 to 300 ten thousand. In view of durability, particularly heat resistance, it is preferable to use a polymer having a weight average molecular weight (Mw) of 70 to 270 ten thousand, more preferably 80 to 250 ten thousand. When the weight average molecular weight (Mw) is less than 50 ten thousand, it is not preferable from the viewpoint of heat resistance. Further, if the weight average molecular weight (Mw) is more than 300 ten thousand, a large amount of a diluting solvent is required to adjust the viscosity for coating, which increases the cost, and thus it is not preferable. The weight average molecular weight (Mw) is a value calculated in terms of polystyrene as measured by GPC (gel permeation chromatography).

The (meth) acrylic polymer can be produced by appropriately selecting known production methods such as solution polymerization, bulk polymerization, emulsion polymerization, and various radical polymerizations. The (meth) acrylic polymer to be obtained may be any copolymer such as a random copolymer, a block copolymer, or a graft copolymer.

The polymerization initiator, chain transfer agent, emulsifier, and the like used in the radical polymerization are not particularly limited and may be appropriately selected and used. The weight average molecular weight (Mw) of the (meth) acrylic polymer can be controlled by the amount of the polymerization initiator, the amount of the chain transfer agent used, and the reaction conditions, and the amount of the polymerization initiator used can be appropriately adjusted according to the type of the (meth) acrylic polymer.

In the solution polymerization, ethyl acetate, toluene, or the like can be used as a polymerization solvent. As a specific example of the solution polymerization, a polymerization initiator may be added under an inert gas stream such as nitrogen gas, and the reaction may be carried out under reaction conditions of usually about 50 to 70 ℃ and about 5 to 30 hours.

< conductive Compound >

The adhesive composition of the present invention preferably contains a conductive compound in addition to the base polymer. Examples of the conductive compound include an ionic compound, an ionic surfactant, a conductive polymer, and a metal oxide.

As the ionic compound, an alkali metal salt and/or an organic cation-anion salt can be preferably used. The alkali metal salt may be an organic salt or an inorganic salt of an alkali metal. The term "organic cation-anion salt" as used herein means an organic salt, and means a salt in which the cation portion is composed of an organic substance, and the anion portion may be either an organic substance or an inorganic substance. The "organic cation-anion salt" is also referred to as an ionic liquid, an ionic solid. The ionic compound may be used in only 1 kind, or 2 or more kinds.

Examples of the alkali metal ion constituting the cation portion of the alkali metal salt include lithium, sodium, and potassium ions. Among these alkali metal ions, lithium ions are preferred.

The anion portion of the alkali metal salt may be composed of an organic substance or an inorganic substance. As the anion portion constituting the organic salt, CH may be used₃COO^－、CF₃COO^－、CH₃SO₃ ^－、CF₃SO₃ ^－、(CF₃SO₂)₃C^－、C₄F₉SO₃ ^－、C₃F₇COO^－、(CF₃SO₂)(CF₃CO)N^－、^－O₃S(CF₂)₃SO₃ ^－、PF₆ ^－、CO₃ ^2－Or an anion portion represented by the following general formulae (1) to (4):

(1)：(C_nF_2n+1SO₂)₂N^－(wherein n is an integer of 1 to 10),

(2)：CF₂(C_mF_2mSO₂)₂N^－(wherein m is an integer of 1 to 10),

(3)：^－O₃S(CF₂)_lSO₃ ^－(wherein l is an integer of 1 to 10),

(4)：(C_pF_2p+1SO₂)N^－(C_qF_2q+1SO₂) (wherein p and q are integers of 1 to 10). In particular, an anion portion containing a fluorine atom is preferably used because an ionic compound having good ion dissociation property can be obtained. As the anion portion constituting the inorganic salt, Cl may be used^－、Br^－、I^－、AlCl₄ ^－、Al₂Cl₇ ^－、BF₄ ^－、PF₆ ^－、ClO₄ ^－、NO₃ ^－、AsF₆ ^－、SbF₆ ^－、NbF₆ ^－、TaF₆ ^－、(CN)₂N^－And the like. As the anion portion, (CF) is preferable₃SO₂)₂N^－、(C₂F₅SO₂)₂N^－And (perfluoroalkylsulfonyl) imide represented by the general formula (1) mentioned above, and particularly preferably (CF)₃SO₂)₂N^－(trifluoromethanesulfonyl) imide.

Specific examples of the organic salt of an alkali metal include: sodium acetate, sodium alginate, sodium lignosulfonate, sodium toluenesulfonate and LiCF₃SO₃、Li(CF₃SO₂)₂N、Li(CF₃SO₂)₂N、Li(C₂F₅SO₂)₂N、Li(C₄F₉SO₂)₂N、Li(CF₃SO₂)₃C、KO₃S(CF₂)₃SO₃K、LiO₃S(CF₂)₃SO₃K, etc., among which LiCF is preferred₃SO₃、Li(CF₃SO₂)₂N、Li(C₂F₅SO₂)₂N、Li(C₄F₉SO₂)₂N、Li(CF₃SO₂)₃C, etc., more preferably Li (CF)₃SO₂)₂N、Li(C₂F₅SO₂)₂N、Li(C₄F₉SO₂)₂A fluorine-containing imide lithium salt such as N, and a (perfluoroalkyl sulfonyl) imide lithium salt is particularly preferable.

Examples of the inorganic salt of an alkali metal include lithium perchlorate and lithium iodide.

The organic cation-anion salt is composed of a cation component and an anion component, and the cation component is composed of an organic substance. Specific examples of the cationic component include: pyridinium cation, piperidinium cation, pyrrolidinium cation, cation having a pyrroline skeleton, imidazolium cation, tetrahydropyrimidinium cation, dihydropyrimidinium cation, pyrazolium cation, pyrazolinium cation, tetraalkylammonium cation, trialkylsulfonium cation, tetraalkylphosphonium cation, and the like.

As the anion component, Cl may be used^－、Br^－、I^－、AlCl₄ ^－、Al₂Cl₇ ^－、BF₄ ^－、PF₆ ^－、ClO₄ ^－、NO₃ ^－、CH₃COO^－、CF₃COO^－、CH₃SO₃ ^－、CF₃SO₃ ^－、(CF₃SO₂)₃C^－、AsF₆ ^－、SbF₆ ^－、NbF₆ ^－、TaF₆ ^－、(CN)₂N^－、C₄F₉SO₃ ^－、C₃F₇COO^－、((CF₃SO₂)(CF₃CO)N^－、^－O₃S(CF₂)₃SO₃ ^－Or an anion component represented by the following general formulae (1) to (4):

(1)：(C_nF_2n+1SO₂)₂N^－(wherein n is an integer of 1 to 10),

(2)：CF₂(C_mF_2mSO₂)₂N^－(wherein m is an integer of 1 to 10),

(3)：^－O₃S(CF₂)_lSO₃ ^－(wherein l is an integer of 1 to 10),

(4)：(C_pF_2p+1SO₂)N^－(C_qF_2q+1SO₂) (wherein p and q are integers of 1 to 10). Among these, an anionic component containing a fluorine atom is preferably used because an ionic compound having good ion dissociation property can be obtained.

In addition, examples of the ionic compound include inorganic salts such as ammonium chloride, aluminum chloride, copper chloride, ferrous chloride, ferric chloride, and ammonium sulfate, in addition to the alkali metal salts and the organic cation-anion salts.

Examples of the ionic surfactant include various surfactants of cationic type (quaternary ammonium salt type, phosphonium salt type, sulfonium salt type, etc.), anionic type (carboxylic acid type, sulfonic acid salt type, sulfuric acid salt type, phosphoric acid salt type, sulfite salt type, etc.), amphoteric type (sulfobetaine type, alkylbetaine type, alkylimidazolium betaine type, etc.) or nonionic type (polyol derivative, β -cyclodextrin inclusion compound, sorbitan fatty acid monoester/diester, polyalkylene oxide derivative, amine oxide, etc.). The ionic surfactant may be used in only 1 kind, or may be used in 2 or more kinds.

The conductive polymer may be a polymer such as a polyaniline-based, polythiophene-based, polypyrrole-based, or polyquinoxaline-based polymer, and among them, polyaniline, polythiophene, or the like which is easily changed into a water-soluble conductive polymer or a water-dispersible conductive polymer is preferably used. Polythiophenes are particularly preferred. The conductive polymer may be used in 1 kind, or 2 or more kinds.

Examples of the metal oxide include tin oxide-based, antimony oxide-based, indium oxide-based, and zinc oxide-based. Among them, tin oxide series is preferable. Examples of the tin oxide-based metal oxide include antimony-doped tin oxide, indium-doped tin oxide, aluminum-doped tin oxide, tungsten-doped tin oxide, a titanium oxide-cerium oxide-tin oxide composite, a titanium oxide-tin oxide composite, and the like, in addition to tin oxide. The metal oxide may be used in only 1 kind, or 2 or more kinds.

Examples of the other conductive compound include polymers having ionic conductivity, such as acetylene black, ketjen black, natural graphite, artificial graphite, titanium black, homopolymers of a monomer having an ionic conductive group of a cationic type (quaternary ammonium salt, etc.), a zwitterionic type (betaine compound, etc.), an anionic type (sulfonate, etc.) or a nonionic type (glycerin, etc.), copolymers of the monomer with other monomers, and polymers having a site derived from an acrylate or methacrylate having a quaternary ammonium salt group; a permanent antistatic agent of a type in which a hydrophilic polymer such as a polyethylene methacrylate copolymer is alloyed with an acrylic resin or the like.

From the viewpoint of high conductivity, excellent dispersibility in a binder, excellent transparency, and storage stability in a binder, an ionic compound is preferably used as the conductive compound.

The mixing ratio of the conductive compound is preferably 0.0001 to 5 parts by weight relative to 100 parts by weight of the base polymer. If the amount of the conductive compound is less than 0.0001 part by weight, the effect of improving the antistatic property may be insufficient. On the other hand, if the conductive compound is more than 5 parts by weight, the durability may be insufficient. The conductive compound is preferably 0.01 parts by weight or more, and more preferably 0.1 parts by weight or more. The conductive compound is preferably 3 parts by weight or less, and more preferably 2 parts by weight or less.

In addition, a crosslinking agent may be contained in the adhesive composition of the present invention. As the crosslinking agent, an organic crosslinking agent or a polyfunctional metal chelate compound can be used. Examples of the organic crosslinking agent include isocyanate crosslinking agents, peroxide crosslinking agents, epoxy crosslinking agents, and imine crosslinking agents. The polyfunctional metal chelate compound is a compound in which a polyvalent metal and an organic compound form a covalent bond or a coordinate bond. Examples of the polyvalent metal atom include Al, Cr, Zr, Co, Cu, Fe, Ni, V, Zn, In, Ca, Mg, Mn, Y, Ce, Sr, Ba, Mo, La, Sn, Ti and the like. Examples of the atom in the organic compound forming a covalent bond or a coordinate bond include an oxygen atom, and examples of the organic compound include an alkyl ester, an alcohol compound, a carboxylic acid compound, an ether compound, and a ketone compound. The crosslinking agent is preferably an isocyanate-based crosslinking agent or a peroxide-based crosslinking agent. The crosslinking agent may be used in only 1 kind, or may be used in 2 or more kinds.

The compounding ratio of the crosslinking agent is preferably 0.01 to 20 parts by weight, more preferably 0.03 to 10 parts by weight, based on 100 parts by weight of the base polymer. If the amount of the crosslinking agent is less than 0.01 part by weight, the cohesive force of the adhesive tends to be insufficient, and foaming may occur during heating, while if the amount is more than 20 parts by weight, the moisture resistance is insufficient, and peeling is likely to occur in a reliability test or the like.

Further, the adhesive composition of the present invention may contain a silane coupling agent. By using the silane coupling agent, durability can be improved. The silane coupling agent may be used in only 1 kind, or may be used in 2 or more kinds.

The amount of the silane coupling agent is preferably 0.001 to 5 parts by weight, more preferably 0.01 to 1 part by weight, still more preferably 0.02 to 1 part by weight, and particularly preferably 0.05 to 0.6 part by weight, based on 100 parts by weight of the base polymer. The amount of the adhesive agent is appropriately selected within the above range in order to improve durability and appropriately maintain adhesive force to an optical member such as a liquid crystal panel.

The pressure-sensitive adhesive composition of the present invention may further contain other known additives, and powders such as colorants and pigments, dyes, surfactants, plasticizers, tackifiers, surface lubricants, leveling agents, softeners, antioxidants, light stabilizers, ultraviolet absorbers, polymerization inhibitors, inorganic or organic fillers, metal powders, particles, foils, and the like may be added as appropriate depending on the application. In addition, a redox system in which a reducing agent is added may be used within a controllable range.

The spacer-equipped adhesive layer of the present invention can be produced by applying a solution containing the adhesive composition to the release layer of the spacer, and then drying the solution to form the adhesive layer. In addition, at least one solvent other than the polymerization solvent may be added newly as appropriate at the time of coating the adhesive composition.

As a coating method of the adhesive composition, various methods can be used. Specifically, there may be mentioned methods such as a roll coating method, a roll lick coating method, a gravure coating method, a reverse coating method, a roll brush coating method, a spray coating method, an immersion roll coating method, a bar coating method, a blade coating method, an air knife coating method, a shower coating method, a die lip coating method, and an extrusion coating method using a die coater or the like.

The thickness of the adhesive layer is not particularly limited, and is about 1 to 100 μm. Preferably 2 to 50 μm, more preferably 2 to 40 μm, and further preferably 5 to 35 μm.

From the viewpoint of imparting conductivity to the spacer-attached pressure-sensitive adhesive layer and suppressing white unevenness of the liquid crystal panel, the surface resistance value of the pressure-sensitive adhesive layer is preferably 1.0 × 10¹²Omega/□ or less, more preferably 1.0X 10¹¹Omega/□ or less, more preferably 1.0X 10¹⁰Omega/□ or less.

< optical film with spacer-containing adhesive layer >

The optical film with a spacer-equipped pressure-sensitive adhesive layer of the present invention is one in which the pressure-sensitive adhesive layer side of the spacer-equipped pressure-sensitive adhesive layer is bonded to at least one surface of the optical film.

The optical film may be one used for forming an image display device such as a liquid crystal display device, and the type thereof is not particularly limited. Examples of the optical film include surface treatment films such as a polarizing film, a retardation plate, an optical compensation film, a brightness enhancement film, and an antireflection film, and optical films obtained by laminating these films.

As the polarizing film, a polarizing film having a transparent protective film on one side or both sides of a polarizing plate is generally used. The polarizing plate is not particularly limited, and various polarizing plates can be used. Examples of the polarizing plate include a material obtained by uniaxially stretching a hydrophilic polymer film such as a polyvinyl alcohol film, a partially formalized polyvinyl alcohol film, or an ethylene-vinyl acetate copolymer partially saponified film, while adsorbing a dichroic substance such as iodine or a dichroic dye, and a polyolefin-based alignment film such as a dehydrated polyvinyl alcohol or a desalted polyvinyl chloride-treated film. Among them, a polarizing plate containing a polyvinyl alcohol film and a dichroic substance such as iodine is preferable. The thickness of these polarizing plates is not particularly limited, but is generally about 80 μm or less.

The polarizing plate may be a thin polarizing plate having a thickness of 10 μm or less. From the viewpoint of thinning, the thickness is preferably 1 to 7 μm. Such a thin polarizing plate is preferable in view of its excellent durability because of its excellent thickness unevenness, excellent visibility, and small dimensional change, and also in view of its thin thickness as a polarizing film.

As a material constituting the transparent protective film, a thermoplastic resin excellent in transparency, mechanical strength, thermal stability, water resistance, isotropy, and the like can be used. Specific examples of such thermoplastic resins include cellulose resins such as triacetylcellulose, polyester resins, polyethersulfone resins, polysulfone resins, polycarbonate resins, polyamide resins, polyimide resins, polyolefin resins, (meth) acrylic resins, cyclic polyolefin resins (norbornene resins), polyarylate resins, polystyrene resins, polyvinyl alcohol resins, and mixtures thereof. Further, although a transparent protective film is bonded to one side of the polarizing plate by an adhesive layer, a thermosetting resin or an ultraviolet curable resin such as a (meth) acrylic, urethane, acrylic urethane, epoxy, or silicone resin can be used as the transparent protective film on the other side. The transparent protective film may contain 1 or more kinds of any suitable additives.

The adhesive used for bonding the polarizing plate and the transparent protective film is not particularly limited as long as it is optically transparent, and various types of materials such as aqueous, solvent, hot melt, radical curing, and cation curing types can be used, but an aqueous adhesive or a radical curing adhesive is preferable.

< image display device >

The image display device of the present invention is configured such that the pressure-sensitive adhesive layer side of the optical film with a pressure-sensitive adhesive layer is bonded to at least one surface of the display panel in a state where the spacer is peeled from the optical film with a pressure-sensitive adhesive layer with a spacer. Examples of the display panel include a liquid crystal panel. The liquid crystal panel may be any type of liquid crystal panel such as TN type, STN type, pi type, VA type, IPS type, or the like.

< method for manufacturing image display device >

The method for manufacturing an image display device of the present invention is a manufacturing method including a roll material preparation step of preparing a long sheet of an optical film with a spacer-attached pressure-sensitive adhesive layer as a roll material; a display panel conveyance preparation step of conveying the display panel to a bonding position for preparation; and a bonding step (RTP bonding step) of bonding the pressure-sensitive adhesive layer-attached optical film exposed by peeling the spacer to the display panel conveyed to the bonding position while pulling out the optical film with the spacer-attached pressure-sensitive adhesive layer from the roll and peeling the spacer from the optical film with the spacer-attached pressure-sensitive adhesive layer by a peeling member.

< coil preparation Process >

The web preparation step is a step of manufacturing an optical film with a spacer-attached pressure-sensitive adhesive layer as a web of a long (strip-shaped) sheet, and the web is not particularly limited and can be manufactured by a conventional method.

< preparation Process for transporting display Panel >

The display panel transport preparation step is a step of transporting the display panel such as a liquid crystal panel to the bonding position, and the transport method is not particularly limited, and the display panel can be transported according to a conventional method.

< RTP bonding Process >

A typical schematic diagram of the RTP bonding process is shown in fig. 3. Immediately before the long piece of the optical film 3 with the spacer-equipped adhesive layer, which is taken out from the roll, is conveyed to the joining position 101, the spacer 1 is peeled off from the optical film 3 with the spacer-equipped adhesive layer by the peeling body 100. The pressure-sensitive adhesive layer 21 of the pressure-sensitive adhesive layer-attached optical film 4 exposed after the peeling of the spacer 1 is bonded to the display panel 5 guided to the bonding predetermined position 101 by the receiving roller 102 by the bonding roller 103, and the image display device is manufactured.

In the RTP bonding step, since the optical film 3 with a pressure-sensitive adhesive layer with a spacer is a long sheet that is not cut, the optical film 4 (or the pressure-sensitive adhesive layer 21) with a pressure-sensitive adhesive layer in a long sheet shape is also in a state of continuing to contact the spacer 1 before being peeled after the peeling of the spacer 1. Thus, even if static electricity is generated in the long sheet-like optical film 4 with a pressure-sensitive adhesive layer (or the pressure-sensitive adhesive layer 21) by peeling the spacer 1, the static electricity can be rapidly transferred to the peeled spacer 1 via the pre-peeling spacer 1, and therefore the peeled spacer 1 functions as a ground, and as a result, the static electricity is attenuated.

The image display device may be manufactured by appropriately assembling components such as a lighting system used as needed after the display panel and the optical film with an adhesive layer are bonded, and then by incorporating a driving circuit, and examples thereof include a method for manufacturing a liquid crystal display device in which an optical film with an adhesive layer is disposed on one side or both sides of a display panel such as a liquid crystal panel, a method for manufacturing a liquid crystal display device in which a backlight or a reflector is used in a lighting system, and the like. In this case, the optical film with an adhesive layer of the present invention may be provided on one side or both sides of a display panel such as a liquid crystal panel. In the case where optical films are provided on both sides, they may be the same or different. In the method for manufacturing a liquid crystal display device, appropriate members such as 1 or 2 or more diffusion layers, antiglare layers, antireflection films, protective plates, prism arrays, lens array sheets, light diffusion sheets, and backlights may be disposed at appropriate positions.

[ examples ]

The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. In each example, parts and% are by weight.

Example 1

< production of spacer >

< formation of oligomer prevention layer >

As the silica-based material, an organosiloxane (Ethyl Silicate 48: COLCOAT) was diluted with isopropyl alcohol to a solid content concentration of 1% to prepare a coating solution. The obtained coating liquid was applied to a polyester film (thickness: 38 μm) as a base film by a gravure coater so that the dried thickness was 50nm, and then dried at 120 ℃ for 30 seconds to form an oligomer prevention layer (1).

< formation of conductive layer >

As the conductive polymer, poly (ethylene dioxythiophene)/polystyrene sulfonic acid (PEDOT/PSS) was used to prepare a solution of water/isopropyl alcohol (1/1: weight ratio) having a solid content concentration of 1%. The obtained solution was applied to the oligomer prevention layer (1) so that the thickness after drying was 100nm, and dried at 80 ℃ for 2 minutes to form the conductive layer (1).

Formation of release layer

A silicone resin (KS-847H: manufactured by shinning Chemicals): 20 parts of curing agent (PL-50T: manufactured by SIGHT CHEMICAL Co., Ltd.): 0.2 part of the solution was diluted with 350 parts of a methyl ethyl ketone/toluene mixed solvent (mixing ratio: 1) to prepare a solution of a silicone-based release agent. The obtained solution of the silicone-based release agent was applied onto the conductive layer (1) by a gravure coater so that the thickness after drying was 100nm, and then dried at 120 ℃ for 30 seconds to form a release layer, thereby obtaining a spacer of example 1 having a structure of polyester film/oligomer-preventing layer (1)/conductive layer (1)/release layer.

Example 2

< production of spacer >

< formation of conductive layer >

As the conductive polymer, poly (ethylene dioxythiophene)/polystyrene sulfonic acid (PEDOT/PSS) was used to prepare a solution of water/isopropyl alcohol (1/1: weight ratio) having a solid content concentration of 1%. The obtained solution was applied to a polyester film (thickness: 38 μm) as a base film so that the dried thickness was 100nm, and dried at 80 ℃ for 2 minutes to form a conductive layer (1).

< formation of oligomer prevention layer >

As the silica-based material, a coating solution was prepared by diluting a silica sol having an average particle size of 0.05 μm with isopropyl alcohol until the solid content concentration became 1%. The obtained coating liquid was applied to the conductive layer (1) by a gravure coater so that the thickness after drying was 50nm, and then dried at 120 ℃ for 30 seconds to form an oligomer prevention layer (2).

Formation of release layer

A spacer of example 2 having a structure of polyester film/conductive layer (1)/oligomer prevention layer (2)/release layer was obtained in the same manner as in example 1, except that in example 1, in the case of < formation of release layer >, the release layer was formed on the oligomer prevention layer (2).

Example 3

< production of spacer >

< formation of conductive layer >

As the conductive polymer, poly (ethylene dioxythiophene)/polystyrene sulfonic acid (PEDOT/PSS) was used, and as the binder resin, a polyurethane resin was used, to prepare a solution of water/isopropyl alcohol (1/1: weight ratio) having a solid content concentration of 0.8%. The weight ratio of the conductive polymer to the binder resin is 10: 1. the obtained solution was coated on a polyester film (thickness: 38 μm) as a base film so that the dried thickness was 100nm, and dried at 80 ℃ for 2 minutes to form a conductive layer (2).

< formation of oligomer prevention layer >

Formation of release layer

A spacer of example 3 having a structure of polyester film/conductive layer (2)/oligomer prevention layer (2)/release layer was obtained in the same manner as in example 2, except that in example 2, the oligomer prevention layer (2) was formed on the conductive layer (2) and the release layer was provided on the oligomer prevention layer (2).

Example 4

< production of spacer >

< formation of oligomer prevention layer >

As a composition containing a polyvinyl alcohol resin, a coating solution was prepared by diluting 70 parts of a polyvinyl alcohol resin (polyvinyl alcohol having a saponification degree of 88 mol% and a polymerization degree of 500), 15 parts of a binder polymer (an aqueous polyester resin obtained by neutralizing and hydrating a polyester mainly composed of isophthalic acid, ethylene glycol, and diethylene glycol with neopentyl glycol and a dicarboxylic acid derivative having an aliphatic dicarboxylic acid anhydride with an amine compound), 10 parts of a crosslinking agent (hexamethoxymethylmelamine), and 5 parts of inorganic particles (silica sol having an average particle diameter of 65 nm) with water to a solid content concentration of 2%. The obtained coating liquid was applied to a polyester film (thickness: 38 μm) as a base film by a gravure coater so that the dried film had a thickness of 50nm, and then the film was stretched at 100 ℃ by introducing the film into a tenter, and then heat-set at 230 ℃ to form an oligomer prevention layer (3).

< formation of conductive layer >

Formation of release layer

In example 1, the spacer of example 4 having the structure of the polyester film/oligomer prevention layer (3)/the conductive layer (1)/the release layer was obtained in the same manner as in example 1 in the case of < formation of the conductive layer > and < formation of the release layer >.

Comparative example 1

< production of spacer >

A spacer of comparative example 1 having a structure of a base material film/oligomer prevention layer (1)/release layer was obtained in the same manner as in example 1, except that the conductive layer (1) was not formed in example 1.

Comparative example 2

< production of spacer >

Oligomer prevention layer formation with conductive agent

As a composition for forming an oligomer prevention layer to which a conductive agent is added, 85 parts of a compound having a nitrogen element (a compound having a pyrrolidinium ring in the main chain: Sharoll DC-303P manufactured by first industrial pharmaceutical company), 10 parts of a polyvinyl alcohol resin (polyvinyl alcohol having a saponification degree of 88 mol% and a polymerization degree of 500), and 5 parts of inorganic particles (silica sol having an average particle diameter of 50 nm) as a conductive material were diluted with water to a solid content concentration of 2% to prepare a coating solution. The obtained coating liquid was applied to a polyester film (thickness: 38 μm) as a base film by a gravure coater so that the dried film had a thickness of 50nm, and then the film was stretched at 100 ℃ by introducing it into a tenter, and then heat-set at 230 ℃ to form an oligomer prevention layer to which a conductive agent was added.

Formation of release layer

A spacer of comparative example 2 having a polyester film/conductive agent-added oligomer prevention layer/release layer structure was obtained in the same manner as in example 1, except that in example 1, in the case of < formation of release layer >, the release layer was formed on the conductive agent-added oligomer prevention layer.

< production of adhesive layer with spacer >

Preparation of acrylic Polymer

A monomer mixture containing 99 parts of butyl acrylate and 1 part of 4-hydroxybutyl acrylate was charged into a reaction vessel equipped with a cooling tube, a nitrogen inlet tube, a thermometer, and a stirrer. Then, 0.1 part of 2, 2' -azobisisobutyronitrile was added as a polymerization initiator together with ethyl acetate to 100 parts of the monomer mixture (solid content), nitrogen gas was introduced while slowly stirring to replace nitrogen gas, and then the polymerization reaction was carried out for 7 hours while maintaining the liquid temperature in the flask at about 60 ℃. Then, ethyl acetate was added to the obtained reaction solution to prepare a solution of an acrylic polymer having a weight average molecular weight (Mw) of 160 ten thousand with the solid content concentration adjusted to 30%.

< preparation of adhesive composition >

A solution of an adhesive composition was prepared by mixing 0.7 parts of 1-ethyl-1-methylpyrrolidinium trifluoromethanesulfonimide and 1.0 part of lithium bis (trifluoromethanesulfonyl) imide (manufactured by Mitsubishi Material Co., Ltd.) as ionic compounds, 0.1 part of trimethylolpropane xylene diisocyanate (manufactured by Mitsui chemical Co., Ltd.: Takenate D110N) and 0.3 part of dibenzoyl peroxide as crosslinking agents, and 0.2 part of gamma-glycidoxypropylmethoxysilane (manufactured by shin-Etsu chemical Co., Ltd.: KBM-403) as silane coupling agents, based on 100 parts of the solid content of the acrylic polymer (A) solution obtained by the above-mentioned procedure.

< formation of adhesive layer >

The solution of the binder composition prepared in the above-described manner was uniformly applied to the release layer of the spacers of examples 1 to 4 and comparative examples 1 to 2 obtained in the above-described manner using a jet coater, and then dried in an air circulation type constant temperature oven at 150 ℃ for 60 seconds to form a binder layer having a thickness of 20 μm on the surface of the release layer, thereby obtaining binder layers with spacers of examples 1 to 4 and comparative examples 1 to 2.

Production of optical film with spacer-carrying adhesive layer

Production of optical film

In order to produce a thin polarizing plate, first, a laminate in which a 9 μm-thick polyvinyl alcohol (PVA) layer was formed on an amorphous polyethylene terephthalate (PET) substrate was subjected to air-assisted stretching at a stretching temperature of 130 ℃ to produce a stretched laminate, then the stretched laminate was dyed to produce a colored laminate, and then the colored laminate was subjected to underwater stretching at a stretching temperature of 65 ℃ in boric acid to produce an optical film laminate including a 4 μm-thick PVA layer integrally stretched with an amorphous PET substrate so that the total stretching ratio was 5.94 times. By such 2-stage stretching, the PVA molecules of the PVA layer formed on the amorphous PET substrate are highly oriented, and an optical film laminate, which constitutes a highly functional polarizing plate in which iodine adsorbed by dyeing is highly oriented in one direction as a polyiodide ion complex, including a PVA layer having a thickness of 4 μm, can be produced. Further, a saponified triacetyl cellulose film having a thickness of 80 μm was laminated to the surface of the polarizing plate of the optical film laminate while applying a polyvinyl alcohol adhesive, and then the amorphous PET substrate was peeled off, thereby producing a polarizing film using a thin polarizing plate.

Production of optical film with spacer-carrying adhesive layer

Then, the pressure-sensitive adhesive layers with spacers of examples 1 to 4 and comparative examples 1 to 2 obtained by the above-described procedure were laminated to the polarizing film using the thin polarizing plate obtained by the above-described procedure, and the pressure-sensitive adhesive layers were transferred to obtain optical films with pressure-sensitive adhesive layers with spacers of examples 1 to 4 and comparative examples 1 to 2.

< manufacture of image display device >

In order to manufacture an image display device by the RTP bonding process shown in fig. 3, long sheets of the optical films with spacer-attached pressure-sensitive adhesive layers of examples 1 to 4 and comparative examples 1 to 2 obtained by the above-described operation were prepared as a roll, and a liquid crystal panel was prepared for conveyance to a bonding position. Thereafter, the optical films with the pressure-sensitive adhesive layer having the spacers of examples 1 to 4 and comparative examples 1 to 2 were drawn out from the roll, the spacers were peeled off from the optical film with the pressure-sensitive adhesive layer having the spacers by a peeling member, and the pressure-sensitive adhesive layer side of the optical film with the pressure-sensitive adhesive layer exposed after peeling of the spacers was bonded to the liquid crystal panel conveyed to the bonding position, thereby producing image display devices (liquid crystal display devices) using the liquid crystal panels of examples 1 to 4 and comparative examples 1 to 2.

The weight average molecular weight (Mw) of the (meth) acrylic polymer obtained by the above procedure was measured by GPC (gel permeation chromatography) under the following conditions.

An analysis device: HLC-8120 GPC, manufactured by Tosoh corporation

Column chromatography: g7000HXL + GMHXL manufactured by Tosoh corporation

Column size: each 7.8mm phi x 30cm

Column temperature: 40 deg.C

Flow rate: 0.8ml/min

Injection amount: 100 μ l

Eluent: tetrahydrofuran (THF)

The detector: differential Refractometer (RI)

Standard sample: polystyrene

The following evaluations were made for the spacers, the spacer-attached adhesive layer, and the spacer-attached adhesive layer of examples 1 to 4 and comparative examples 1 to 2 obtained in the above-described manner. The evaluation results are shown in table 1.

< method for measuring surface resistance value of mold release layer >

The surface resistance value (Ω/□) of the surface of the release layer was measured using MCP-HT 450 manufactured by Mitsubishi chemical Analytech corporation for the spacers of examples 1 to 4 and comparative examples 1 to 2 obtained in the above-described manner.

< method for measuring surface resistance value of adhesive layer >

The surface resistance value (Ω/□) of the spacer-attached adhesive layers of examples 1 to 4 and comparative examples 1 to 2 obtained in the above-described manner was measured using MCP-HT 450 manufactured by Mitsubishi chemical Analytech.

< method for measuring elution amount of PET oligomer >

The optical films with spacer-attached pressure-sensitive adhesive layers of examples 1 to 4 and comparative examples 1 to 2 obtained in the above-described manner were left at 60 ℃ and 90% RH for 500 hours, and then the spacers were removed. About 0.025g of the adhesive layer (sample) was collected from the adhesive layer-attached polarizing film, 1ml of chloroform was added and shaken at room temperature for 18 hours, and then 5ml of acetonitrile was added to conduct extraction and shaken for 3 hours. The obtained solution was filtered through a 0.45ml membrane filter, and the sample was adjusted. The standard PET oligomer of trimer was adjusted to a certain concentration to prepare a calibration curve, and the amount (ppm) of PET oligomer contained in the adhesive was determined using the calibration curve. The calibration curve was prepared by measuring with HPLC using a sample having a known PET oligomer concentration (ppm).

HPLC apparatus: 1200 series manufactured by Agilent Technologies

Measurement conditions

A chromatographic column: ZORBAX SB-C18 manufactured by Agilent Technologies

Column temperature: 40 deg.C

Column flow rate: 0.8ml/min

The eluent composition is as follows: water/acetonitrile reverse phase gradient condition

Injection amount: 5 μ l

A detector: PDA (personal digital Assistant)

The quantitative method comprises the following steps: after a standard sample of PET oligomer trimer was dissolved in chloroform, the solution was diluted with acetonitrile to prepare a standard sample at a certain concentration. A calibration curve was prepared from the HPLC area and the preparation concentration, and the amount of PET oligomer eluted from the sample was determined.

The amount of PET oligomer eluted is preferably 30ppm or less, more preferably 20ppm or less, and still more preferably 10ppm or less.

The liquid crystal display devices of examples 1 to 4 and comparative examples 1 to 2 obtained by the above-described operation were evaluated as follows. The evaluation results are shown in table 1.

< evaluation of white unevenness >

The liquid crystal display devices of examples 1 to 4 and comparative examples 1 to 2 obtained by the above-described operation were provided in a backlight. The end of the liquid crystal display device is touched by a hand, and white unevenness occurs in the liquid crystal panel. The time taken for the white unevenness to disappear was measured. The disappearance time is preferably 200 seconds or less, more preferably 100 seconds or less, further preferably 50 seconds or less, and particularly preferably 20 seconds or less.

[ Table 1]

As shown in table 1, examples 1 to 4 of the present invention gave good results in any evaluation items. On the other hand, in comparative examples 1 to 2, results inferior to those in examples 1 to 4 were obtained in any evaluation items. As is apparent from the above results, the present invention can provide a spacer-attached pressure-sensitive adhesive layer which can prevent the occurrence of defects in a liquid crystal panel due to luminance unevenness caused by bright spots by suppressing elution of oligomers contained in a base film such as a polyester film used for a spacer into the pressure-sensitive adhesive layer, can suppress white unevenness of the liquid crystal panel even when the above-described RTP bonding step is applied in the production of a liquid crystal display device, and can provide an optical film with a spacer-attached pressure-sensitive adhesive layer.

Description of the symbols

1: the spacer is provided with a plurality of spacers,

2: a layer of adhesive with a spacer that is,

3: an optical film with a spacer-bearing adhesive layer,

4: an optical film having an adhesive layer is provided,

5: a display panel, a display unit and a display unit,

11: a base material film,

12: a demoulding layer is arranged on the surface of the base material,

13: an oligomer prevention layer for preventing the generation of a high-molecular-weight oligomer,

14: a conductive layer is formed on the substrate,

21: a layer of an adhesive agent, wherein the adhesive agent,

31: an optical film comprising a first layer and a second layer,

100: the stripping body is used for stripping the paper,

101: the position of the pasting is set,

102: a receiving roller for receiving the liquid crystal,

103: pasting roller

Claims

1. An adhesive layer with a spacer, characterized in that,

is a spacer-bearing adhesive layer having an adhesive layer on the spacer,

the spacer has a release layer on a base film, and an oligomer prevention layer and a conductive layer between the base film and the release layer,

the adhesive layer is provided on the release layer of the spacer,

the adhesive layer is a layer formed from an adhesive composition containing a base polymer and a conductive compound,

the surface resistance value of the demoulding layer is 1.0 multiplied by 10¹²Omega/□ or less.

2. The spacer-equipped adhesive layer according to claim 1,

the oligomer prevention layer is a layer formed from a composition containing a silica-based material and/or a polyvinyl alcohol-based resin.

3. The spacer-equipped adhesive layer according to claim 1 or 2,

the conductive layer is a layer formed of a conductive composition containing a conductive polymer.

4. The spacer-equipped adhesive layer according to claim 1 or 2,

the surface resistance value of the adhesive layer is 1.0 multiplied by 10¹²Omega/□ or less.

5. An optical film having an adhesive layer with a spacer,

the pressure-sensitive adhesive layer side of the spacer-equipped pressure-sensitive adhesive layer spacer according to any one of claims 1 to 4 is bonded to at least one surface of an optical film.

6. An image display device is characterized in that,

the pressure-sensitive adhesive layer side of the optical film with a pressure-sensitive adhesive layer, in which the spacer is peeled from the optical film with a pressure-sensitive adhesive layer with a spacer according to claim 5, is bonded to at least one surface of the display panel.

7. A method of manufacturing an image display device, characterized in that,

the method for manufacturing an image display device according to claim 6, comprising:

a roll preparation step of preparing a long sheet of the optical film with the spacer-attached pressure-sensitive adhesive layer according to claim 5 as a roll;

a display panel conveyance preparation step of conveying the display panel to a bonding position for preparation; and

and a bonding step of bonding the pressure-sensitive adhesive layer-attached optical film exposed by peeling the spacer to the display panel conveyed to the bonding position while the spacer is peeled off from the optical film with the spacer-attached pressure-sensitive adhesive layer by a peeling member by pulling out the optical film with the spacer from the roll.