JP5239241B2 - Laminated body for protecting optical material, electroluminescence optical element using the same, and electrophoretic display panel - Google Patents

Description

  The present invention relates to a laminate for protecting an optical material that is highly transparent and has a high barrier property such as oxygen and water vapor, an electroluminescence display element (hereinafter abbreviated as an EL element) using the same, and an electrophoretic display. In particular, the present invention relates to a laminate for protecting an optical material in which a protective film to be peeled off in use is integrated, an EL element using the same, and an electrophoretic display panel.

  As transparent plastic materials used for surface substrates such as displays, polyester-based substrates such as polyethylene terephthalate (hereinafter abbreviated as PET) and polyethylene naphthalate (hereinafter abbreviated as PEN) have been known.

  In order to protect the surface of the plastic material used for the surface base material from scratches and dirt during processing, a polyethylene base material layer and an adhesive layer of an ethylene vinyl acetate copolymer system or an ethylene-α-olefin copolymer system are used. A surface protective film having a self-adhesive property and a peelability has been known.

  However, surface substrates and protective films made of known materials as described above do not have sufficient barrier properties against oxygen, water vapor, and other gases that alter the contents, and protection and storage properties of display elements such as EL elements. There was no effect on improvement.

  Therefore, a barrier resin film having a relatively excellent barrier property as a surface substrate, for example, a vinylidene chloride resin film, a polyvinyl alcohol and ethylene vinyl copolymer film, a resin film such as polyacrylonitrile, or a laminated film of these resins Etc. have been mainly used. However, barrier resin films and their laminated films are highly temperature-humidity dependent and cannot maintain a high level of barrier properties. In addition, vinylidene chloride, polyacrylonitrile, etc. generate harmful substances when discarded or incinerated. There was a problem such as possible.

  Therefore, as a transparent plastic material having moisture resistance that overcomes these disadvantages, for example, inorganic oxides such as silicon oxide, aluminum oxide, and magnesium oxide as described in Patent Document 3, A barrier laminated film formed as a transparent film on a plastic film by a forming means such as a sputtering method has been put on the market. The present inventor also has a laminated film composed of a transparent resin barrier film layer and a thermal adhesive film layer described in Patent Document 1, and a laminated film composed of at least two transparent resin barrier film layers and an adhesive layer described in Patent Document 2. Provide film.

However, if the total thickness of the surface base material and the protective film base material on which the transparent barrier film of the inorganic oxide described above is combined is thin, handling at the time of stacking and assembling the display body is difficult, and further, punching, etc. Various external forces applied at the time of processing cause damage to the barrier material, and there is a problem that the original barrier performance cannot be exhibited. In addition, if the protective film has a strong adhesive force, when the protective film is peeled off during use of the display body, the barrier material is damaged such as generation of microcracks, and the original barrier performance cannot be exhibited. there were.
JP 2005-224965 A WO 2004/101276 Japanese Patent Publication No.63-28017

  The present invention was made in order to solve the problems of the prior art described in the background art above, and is an optical material protection layered and integrated with a protective film that is highly transparent and has high barrier properties such as oxygen and water vapor. It is a laminate for use, and it is easy to handle and has good processability. In particular, it provides a surface substrate whose barrier properties do not deteriorate even when the protective film is peeled off during use.

  Another object of the present invention is to provide an electroluminescent light emitting device and an electrophoretic display panel using a laminate for protecting an optical material that is highly transparent and has a high barrier property such as oxygen and water vapor. Objective.

The invention according to claim 1 of the present invention is a laminate for protecting an optical material for protecting the surface of a surface base material of a display body,
It is transparent and has a barrier property, which is a laminate of a protective film that peels and removes in the combined form of an adhesive layer and an adhesive substrate, and a surface substrate that has barrier properties and constitutes the surface of the display element itself. A laminate for protecting an optical material, wherein the surface base material includes a transparent vapor-deposited layer of an inorganic oxide deposited on the transparent base material as a transparent barrier layer, and the peel strength of the adhesive layer is the surface base material. For 100 mN / 25 mm or less,
The inorganic oxide includes at least one selected from the group consisting of aluminum oxide, silicon oxide, and magnesium oxide, and the transparent substrate is a plastic film having a thickness of 9 to 50 μm,
The adhesive layer is an acrylic adhesive;
The pressure-sensitive adhesive base layer is a polyester film.

Further, the invention according to claim 2 of the present invention is the transparent electrode layer, the electroluminescence light emitting layer, and the electroluminescence light emitting layer provided on the back side of the surface base material of the laminate for protecting an optical material according to claim 1. An electroluminescent light-emitting element comprising a laminate having a dielectric layer or insulating layer provided thereon and a back electrode layer provided thereon.

Moreover, the invention which concerns on Claim 3 of this invention is a transparent electrode layer provided on the surface base-material back side of the laminated body for optical material protection in any one of Claims 1-2 , On this transparent electrode layer An electrophoretic display layer including an electrophoretic particle and an insulating fluid that disperses the electrophoretic particle, and a laminate having a back electrode provided on the electrophoretic display layer. This is an electrophoretic display panel.

According to a fourth aspect of the present invention, in the electrophoretic display panel according to the third aspect , the electrophoretic display layer includes a capsule encapsulating an insulating fluid in which electrophoretic particles are dispersed. It is an electrophoretic display panel characterized by having.

  The laminate for protecting an optical material of the present invention is a rigid laminate for protecting an optical material, which is integrated with a protective film, is highly transparent, and has a high barrier property such as oxygen and water vapor. The display element is suitable for processing. In particular, it is possible to provide a surface base material that does not deteriorate its barrier properties by peeling off the protective film when the display body is used. Therefore, after sealing the phosphor such as the EL element, it is possible to provide an EL element that prevents moisture from entering from the outside and does not cause deterioration of the phosphor due to moisture or decrease in light emission efficiency.

  Hereinafter, the laminated body for protecting an optical material of the present invention will be described below based on one embodiment. FIG. 1 is a cross-sectional view showing a typical example of the optical material protecting laminate of the present invention.

  The laminate 10 for protecting an optical material of the present invention has a protective film 30 that is peeled and removed in use in a composite form of an adhesive base layer 4 and an adhesive layer 3, and has a barrier property and itself constitutes the surface of a display element. A laminate for protecting an optical material, wherein the surface substrate 20 is laminated and integrated, and the peel strength of the adhesive layer is 100 mN / 25 mm or less with respect to the surface substrate.

  The surface base material 20 includes a transparent vapor deposition layer of inorganic oxide deposited on the transparent base material 1 as the barrier layer 2. The transparent substrate 1 is required to have a high transparency, heat resistance, and mechanical strength as a vapor deposition substrate for inorganic oxide while constituting the display element surface. Examples of the transparent substrate 1 include polyethylene terephthalate (PET) resin, polyethylene naphthalate (PEN) resin, olefin-based polypropylene (PP) resin, and polyethylene (PE) resin. In some applications, an engineering plastic film such as polyimide is used. Among them, biaxially stretched polyethylene terephthalate (PET) is most preferable from the viewpoint of processability and cost for general purposes. The thickness of the transparent substrate 1 is preferably 9 to 50 μm. If it is less than 9 μm, film formation becomes difficult, and film failure tends to occur due to shrinkage caused by heat during vapor deposition. When it exceeds 50 μm, the processing efficiency such as vapor deposition or lamination processing tends to decrease.

  As the inorganic oxide deposited on the transparent substrate, at least one selected from the group consisting of aluminum oxide, silicon oxide, and magnesium oxide, or two or more can be used. The thickness of the transparent vapor-deposited layer 2 of inorganic oxide is preferably in the range of 5 to 300 nm, and more preferably 10 to 150 nm in terms of stable barrier properties.

  As a method of forming the transparent vapor deposition layer 2 made of an inorganic oxide on the transparent substrate 1 such as a polyester film, a normal vacuum vapor deposition method can be used. Further, other thin film forming methods such as sputtering, ion plating, plasma vapor deposition (CVD), and the like can also be used. In addition, in order to increase the transparency of the deposited film, reactive vapor deposition in which oxygen gas or the like is blown can be performed during the deposition. In order to enhance the barrier property of the transparent vapor deposition layer, the transparent substrate surface is coated immediately before vapor deposition or surface treatment such as low temperature plasma, or some organic or inorganic substance on the vapor deposition layer surface after vapor deposition. It is also possible to coat.

As for the barrier property of the surface substrate 20 including the transparent vapor-deposited layer 2 of inorganic oxide, the water vapor permeability is preferably 0 to 50 g / m ² · day · 40 ° C. 90% RH. In the present invention, the effectiveness is exhibited particularly in applications where a water vapor permeability is as low as 1.0 g / m ² · day · 40 ° C. and 90% RH or less, that is, high barrier properties are required. The water vapor transmission rate used here is measured under the conditions of a temperature of 40 ° C. and a humidity of 90% RH using a water vapor transmission rate measuring device (PERMATRAN 3/31 manufactured by Modern Control Co., Ltd.) according to JIS K7129B method. it can.

  As the pressure-sensitive adhesive layer 3 used in the present invention, one having excellent transparency is used. Examples of the adhesive material constituting the adhesive layer 3 include acrylic, rubber, urethane, vinyl ether, and silicon. Depending on the application, ethylene-α-olefin copolymers and polyester-based pressure-sensitive adhesives are used. In particular, acrylic resins mainly composed of acrylic prepolymers or acrylic monomers have transparency, light resistance, and cost. From the point of view, it is preferable.

  Acrylic resins include vinyl monomers containing acrylic groups, vinyl monomers having epoxy groups, vinyl monomers having alkoxyl groups, vinyl monomers having ethylene oxide groups, vinyl monomers having amino groups, vinyl monomers having amide groups, halogens Vinyl monomer having atom, vinyl monomer having phosphoric acid group, vinyl monomer having sulfonic acid group, vinyl monomer having silane group, vinyl monomer having phenyl group, vinyl monomer having benzyl group, vinyl having tetrahydrofurfuryl group Those obtained by polymerizing monomers and other monomers containing copolymerizable monomers by any method can be used.

Various additives, for example, natural resins such as rosin, modified rosin, rosin and modified rosin derivatives, polyterpene resins, terpene modified products, aliphatic hydrocarbon resins, cyclopentadiene, for controlling the physical properties of the acrylic resin. Resins, aromatic petroleum resins, phenolic resins, alkyl-phenol-acetylene resins, coumarone-indene resins, vinyltoluene-α-methylstyrene copolymers and other tackifiers, anti-aging agents, stabilizers , And softeners can be added as necessary. These can be used in combination of two or more as required. Further, in order to increase light resistance, an organic ultraviolet absorber such as benzophenone or benzotriazole can be added. The adhesive substrate 4 of the protective film 30 may be in the form of a film. In particular, a polyethylene terephthalate (PET) film is used such as polypropylene or polyethylene depending on the application. However, the thickness of the polyethylene terephthalate (PET) film that has been stretched in the biaxial direction among polyester films in consideration of mechanical strength, heat resistance, dimensional stability, workability, versatility, and cost as a protective film 12 μm to 75 μm is most preferable.

  As a method for forming the pressure-sensitive adhesive layer 3, a pressure-sensitive adhesive is applied to the laminated surface of either the pressure-sensitive adhesive substrate 4 or the surface substrate 20, and if necessary, is dried to form the pressure-sensitive adhesive layer 3, and the other substrate is laminated. And laminate. A reverse roll coater, a knife coater, a bar coater, a reverse gravure coater, a die coater, or the like is used as an adhesive application device. The application amount of the pressure-sensitive adhesive is preferably in the range of 1 to 30 μm as the thickness of the pressure-sensitive adhesive layer 3 to be formed.

  As a surface base material that itself constitutes the surface of the display element, when a 12 μm-thick inorganic oxide-deposited transparent barrier film (GX-PF, manufactured by Toppan Printing Co., Ltd.) already on the market is used alone, the surface Since the base material has no waist and lacks suitability for processing, it is very difficult to perform display body formation or punching as an element as it is. In addition, since the transparent vapor-deposited film of inorganic oxide is weak against physical impact and lacks flexibility compared to the base material, it alone cannot follow deformations such as wrinkles and expansion / contraction of the base material, and micro cracks etc. And the barrier performance is reduced. Then, it applies as a laminated body which can improve workability by sticking a protector. Here, the protector is used to protect the surface substrate from physical impacts such as scratches and to provide processing suitability such as protecting the surface substrate from various contaminations during the process, but it is peeled off and removed during use. In view of resources and costs, it is required that the material be as thin as possible.

In addition, the laminate for protecting an optical material of the present invention does not damage the transparent vapor-deposited layer of the inorganic oxide by generating stress due to curing shrinkage or the like when laminating and processing the display body. In order to prevent the deterioration, the protective film in the form of a composite of the surface base material of the adhesive layer and the adhesive base material and the surface base material having a barrier property and constituting the surface of the display element itself are laminated and integrated. The peel strength at the interface between the adhesive base layer and adhesive layer protective film to be peeled off during use and the surface base material that has barrier properties and itself constitutes the surface of the display element peels the protective film 180 degrees. It is necessary to be 100 mN / 25 mm or less. When the adhesive strength is strong, the surface base film is pulled by the protective film, stress is applied to the transparent vapor deposition layer, and micro cracks are generated in the inorganic oxide film, resulting in a decrease in barrier properties. The adhesive strength is measured in accordance with JIS Z 0237 by peeling off a 25 mm wide protective film 180 degrees and measuring the strength at that time with a tensile tester.

  The laminate for protecting an optical material of the present invention can be suitably used for an optical component or the like. An example of the electroluminescence light emitting device of the present invention is, as shown in FIG. 2, a transparent layer made of, for example, indium tin oxide connected to the terminal 11 provided on the back side of the surface base material 20 of the optical material protecting laminate 10. It is connected to the electrode layer 5, the electroluminescent light emitting layer 6 provided on the transparent electrode layer, the dielectric layer or insulating layer (not shown) provided on the electroluminescent light emitting layer, and the terminal 11 provided thereon. For example, a laminated body having a back electrode layer 8 made of metal is provided and sealed with a sealant 9. Each electrode layer, insulating layer, dielectric layer, and electroluminescent light emitting layer can be formed using a known method such as vapor deposition and sputtering.

  Further, as shown in FIG. 3, the electrophoretic display panel of the present invention is made of, for example, indium tin oxide formed in a predetermined pattern provided on the back side of the surface base material 20 of the optical material protecting laminate 10. An electrophoretic display layer 70 including a pixel electrode 50, a switching element (not shown), electrophoretic particles provided on the pixel electrode and an insulating fluid that disperses the electrophoretic particles, and the electrophoretic display layer. The laminated body having the provided back electrode 80 is provided and sealed with a sealant 90.

  In the electrophoretic display panel of the present invention, the electrophoretic display layer 70 includes microcapsules enclosing an insulating fluid in which the electrophoretic particles are dispersed. In the microcapsule, white particles, black particles, and an insulating solution in which these particles are dispersed are enclosed in a coating.

  Hereinafter, specific examples of the present invention will be described together with comparative examples.

<Example 1>
A surface base material that has a barrier property and constitutes the surface of the display element itself is fixed to 12 μm of a transparent vapor deposition film (GX-PF) manufactured by Toppan Printing Co., Ltd., which is excellent in water vapor barrier property, and is a protective film 4, as shown in FIG. 4, a 100 μm PET film as the pseudo contents 13 is attached to the surface base material side, the protective film 30 is peeled 180 degrees, and then the surface base material, that is, transparent The water vapor barrier of the deposited film was measured. The obtained results are shown in Table 1. In addition, according to the catalog value, the vapor barrier of the single substance of GX-PF is 0.05 g / m < ² > / day * 40 degreeC90% RH.

表１に示すように、本発明の積層体は、保護フィルム剥離後も水蒸気バリア性能が維持されていたが、比較例の粘着力が１００ｍＮ／２５ｍｍを越えたものはバリア性が低下していた。

As shown in Table 1, in the laminate of the present invention, the water vapor barrier performance was maintained even after the protective film was peeled off, but when the adhesive strength of the comparative example exceeded 100 mN / 25 mm, the barrier property was lowered. .

It is sectional drawing explaining an example of the laminated body for optical material protection of this invention. It is sectional drawing explaining typically an example of the electroluminescent light emitting element of this invention. It is sectional drawing which illustrates typically an example of the electrophoretic display panel of this invention. It is sectional drawing which illustrates typically the state which peels a protective film 180 degree | times.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Transparent base material 2 ... Transparent vapor deposition layer 3 ... Adhesive layer 4 ... Adhesive base material 10 ... Laminated body for optical material protection 20 ... Surface base material 30 ... protective film 5 50 ... Transparent electrode 6 ... Electroluminescence light emitting layer 7 ... Display area 8, 80 ... Back electrode layer 9, 90 ... Sealant 11, 12 ... Terminal 13 ... Pseudo contents

Claims (4)

A laminate for protecting an optical material that protects a surface of a surface base material of a display body,
It is transparent and has a barrier property, which is a laminate of a protective film that peels and removes in the combined form of an adhesive layer and an adhesive substrate, and a surface substrate that has barrier properties and constitutes the surface of the display element itself. A laminate for protecting an optical material, wherein the surface base material includes a transparent vapor-deposited layer of an inorganic oxide deposited on the transparent base material as a transparent barrier layer, and the peel strength of the adhesive layer is the surface base material. For 100 mN / 25 mm or less,
The inorganic oxide includes at least one selected from the group consisting of aluminum oxide, silicon oxide, and magnesium oxide, and the transparent substrate is a plastic film having a thickness of 9 to 50 μm,
The adhesive layer is an acrylic adhesive;
The said adhesive base material layer is a polyester film, The laminated body for optical material protection characterized by the above-mentioned.   A transparent electrode layer, an electroluminescent light emitting layer, and a dielectric layer or an insulating layer provided on the electroluminescent light emitting layer provided on the back side of the surface substrate of the laminate for protecting an optical material according to claim 1; And an electroluminescent light emitting device comprising a laminate having a back electrode layer provided thereon.   A transparent electrode layer provided on the back surface side of the surface base material of the laminate for protecting an optical material according to claim 1, and the electrophoretic particles and the electrophoretic particles provided on the transparent electrode layer are dispersed. An electrophoretic display panel comprising: an electrophoretic display layer containing an insulating fluid; and a laminate having a back electrode provided on the electrophoretic display layer.   4. The electrophoretic display panel according to claim 3, wherein the electrophoretic display layer includes a capsule encapsulating an insulating fluid in which electrophoretic particles are dispersed.

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