JP2000258627A - Optical member and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method by which the sticking contamination of a laminated body due to penetration between layers of the laminated body is suppressed and edge parts of an adhesive layer are efficiently covered to impart nonstickiness and to obtain an optical member less liable to cause trouble in conveyance, a lack of an adhesive and contamination with the adhesive on side faces of an adhesive layer even in transport, assembling work, etc., and less liable to cause optical abnormality. SOLUTION: The optical member comprises a laminated body having at least an optical substrate 1 and an adhesive layer 2 and has a nonsticky spray coating film 4 on edge parts of the adhesive layer. A quick-drying coating material which forms a nonsticky coating film is sprayed on side faces of a stack of plural laminated bodies having at least an optical substrate and an adhesive layer to form a nonsticky spray coating film on edge parts of the adhesive layer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical member in which chipping or dirt on a side surface of an adhesive layer provided on an optical substrate is prevented, and a method for producing the same.

[0002]

BACKGROUND OF THE INVENTION Optical substrates such as a polarizing plate and a retardation plate used for forming a liquid crystal display (LCD) and the like are used, for example, with a polarizing plate for the purpose of preventing quality variations and increasing the efficiency of LCD assembly and the like. An adhesive layer is previously formed on an optical base material, such as an elliptically polarizing plate in which a retardation plate is laminated in advance through an adhesive layer, or an optical member in which an adhesive layer for bonding a polarizing plate to another member such as a liquid crystal cell is previously provided. It is practically used as a laminate provided with.

However, if the optical member made of the above-mentioned laminate is subjected to transportation or assembling work or the like with the side surface of the adhesive layer being exposed, the optical member adheres to the guide surface of the assembly line and disturbs the transportation. Since there are problems such as a decrease in assembly efficiency and inducing visual impairment due to glue chipping or glue contamination on the side of the adhesive layer, measures to prevent non-adhesion have been taken on the side (edge) of the adhesive layer. I have.

Conventionally, as an optical member in which the edge of the adhesive layer is treated, a transparent film formed by applying a solution of a water repellent or a release agent with a brush or a roll has been known.
In this case, since it is difficult to perform uniform processing on the side surface of the thin layer in the single processing, the optical members are usually processed by stacking a plurality of optical members. However, there has been a problem that optical components that cause adhesion contamination due to a slight intrusion of the coating solution between the layers of the stack occur.

[0005] The above-mentioned adhesion contamination is difficult to detect because it is slight due to the transparent film. On the other hand, even with the slight adhesion contamination in the optical member, similar to the above-mentioned glue chipping and the like, the refractive index is abnormal. It becomes an optical abnormal point, and abnormal phenomena due to the abnormal point are enlarged and noticeable due to a diffraction effect, a scattering effect, and the like, which is fatal as an optical member and makes practical use difficult.

[0006]

SUMMARY OF THE INVENTION The present invention is directed to a method of transporting and assembling to obtain a method capable of effectively preventing the adhesion contamination due to intrusion between the layers of a stacked body, covering the end of the adhesive layer efficiently, and performing a non-adhesion treatment. It is an object of the present invention to provide an optical member which is less likely to cause a conveyance obstacle, a glue chip on an adhesive layer side surface, a glue contamination, and the like even when used for work or the like, and which is less likely to cause an optical abnormality.

[0007]

According to the present invention, there is provided an optical member comprising a laminate having at least an optical base material and an adhesive layer, wherein the laminate has a non-adhesive spray coating on an edge of the adhesive layer. And spraying a quick-drying paint that forms a non-adhesive coating film on at least the side surfaces of the plurality of stacks of the laminate having the optical base material and the adhesive layer, thereby forming a non-adhesive coating on the side edge of the adhesive layer in the laminate. An object of the present invention is to provide a method for producing an optical member, which comprises forming an adhesive spray coating film.

[0008]

According to the present invention, a non-adhesive coating film covering the end of the adhesive layer can be efficiently formed by the spraying method of a quick-drying paint, and the coating film can be formed in a non-contact manner. The liquid does not easily enter between the layers of the stack. As a result, it is possible to obtain an optical member that is unlikely to cause adhesion contamination due to the infiltration of the spray liquid and to cause an optical abnormality, and is less likely to cause a transportation obstacle, chipping of adhesive on the side of the adhesive layer, adhesive contamination, and the like.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The optical member according to the present invention comprises a laminate having at least an optical base material and an adhesive layer, and has a non-adhesive spray coating film on an edge of the adhesive layer in the laminate. An example is shown in FIG. 1 is an optical substrate, 2
Is an adhesive layer, 4 is a spray coating, and 3 is a separator.

In the production of the optical member, for example, a quick-drying paint for forming a non-adhesive coating film is sprayed on at least the side surfaces of a plurality of stacks of a laminate having an optical base material and an adhesive layer. It can be carried out by a method of forming a non-adhesive spray coating on the edge of the adhesive layer in the laminate.

As the optical substrate, for example, an appropriate substrate such as a polarizing plate or a retardation plate used for forming a liquid crystal display device or an elliptically polarizing plate obtained by laminating them can be used, and the type thereof is not particularly limited. Therefore, the laminate may be formed using two or three or more optical substrates.
The polarizing plate may be of a reflection type or the like, and the retardation plate may be a plate having a proper purpose such as a half-wave plate or a quarter-wave plate or viewing angle compensation. In the case of a lamination type optical substrate such as the above-mentioned elliptically polarizing plate, the lamination may be performed via an appropriate bonding means such as an adhesive layer.

Incidentally, specific examples of the above-mentioned polarizing plate include iodine and / or iodine on a hydrophilic polymer film such as a polyvinyl alcohol-based film, a partially formalized polyvinyl alcohol-based film, and an ethylene / vinyl acetate copolymer-based partially saponified film. Examples thereof include a film obtained by adsorbing a dichroic dye and stretching, and a polarizing film made of a polyene oriented film such as a dehydrated product of polyvinyl alcohol or a dehydrochlorinated product of polyvinyl chloride. The thickness of the polarizing film is usually 5 to 80 μm, but is not limited thereto. The polarizing film may have a transparent protective layer such as a protective film on one or both sides.

On the other hand, the reflection type polarizing plate is provided with a reflection layer on the polarizing plate, and is used to form a liquid crystal display device or the like of a type that reflects and reflects incident light from the viewing side (display side). In addition, there is an advantage that a built-in light source such as a backlight can be omitted, and the thickness of the liquid crystal display device can be easily reduced. The reflective polarizing plate can be formed by an appropriate method such as a method in which a reflective layer made of metal or the like is provided on one surface of the polarizing plate via a transparent protective layer or the like as necessary. The above-mentioned polarizing plate, in particular, the transparent protective layer provided on one side or both sides of the polarizing film as needed can also serve as the protective film.

Specific examples of the reflective polarizing plate include a transparent protective layer which is matted if necessary, and a reflective layer formed by attaching a foil or a vapor-deposited film made of a reflective metal such as aluminum to one surface of the transparent protective layer. can give. Further, there may be mentioned, for example, those in which fine particles are contained in the transparent protective layer to form a fine surface uneven structure, and a reflective layer having a fine uneven structure is provided thereon. The reflective layer is used in a state where the reflective surface is covered with a transparent protective layer, a polarizing plate, or the like, in order to prevent a decrease in reflectance due to oxidation, and to maintain the initial reflectance for a long period of time, and to separately provide a protective layer. Is more preferable.

The reflective layer having the fine uneven structure described above has an advantage that the incident light is diffused by irregular reflection to prevent directivity and glaring appearance, and that unevenness in brightness can be suppressed.
Further, the transparent protective layer containing fine particles also has an advantage that the incident light and the reflected light thereof are diffused when transmitting the light and the unevenness of light and darkness can be further suppressed. The reflective layer having a fine uneven structure reflecting the fine uneven structure on the surface of the transparent protective layer is formed by, for example, making the metal transparent by an appropriate method such as an evaporation method such as a vacuum evaporation method, an ion plating method, or a sputtering method, or a plating method. It can be performed by a method of directly attaching to the surface of the protective layer.

The formation of the above-mentioned protective film, which is disposed as necessary for the purpose of protecting the surface of the optical base material, and the transparent protective layer of the polarizing plate, include transparency, mechanical strength, thermal stability, and moisture. A polymer having excellent shielding properties and the like are preferably used. Examples thereof include polyester resins and acetate resins, polyethersulfone resins and polycarbonate resins, polyamide resins and polyimide resins, polyolefin resins and acrylic resins, or acrylic, urethane and acrylic urethane resins. And thermosetting resins such as epoxy resins and silicone resins, and ultraviolet curing resins.

The transparent protective layer may be formed by an appropriate method such as a method of applying a polymer or a method of laminating a film, and the thickness may be appropriately determined. Generally 500 μm
Hereinafter, the thickness is preferably 1 to 300 μm, particularly 5 to 200 μm. The fine particles to be contained in the formation of the transparent protective layer having the fine surface irregularity structure include, for example, an average particle size of 0.5 to 5
Transparent inorganic fine particles of 0 μm silica, alumina, titania, zirconia, tin oxide, indium oxide, cadmium oxide, antimony oxide, and the like, and organic fine particles of a crosslinked or uncrosslinked polymer, etc. Fine particles are used. The amount of fine particles used is 1
It is common to use 2 to 50 parts by weight, especially 5 to 25 parts by weight, per 100 parts by weight.

On the other hand, as a specific example of the above retardation plate, a film made of a suitable polymer such as polycarbonate, polyvinyl alcohol, polystyrene, polymethyl methacrylate, polypropylene, other polyolefin, polyarylate, or polyamide is stretched. Birefringent film or liquid crystal polymer oriented film,
Examples thereof include a film in which an alignment layer of a liquid crystal polymer is supported by a film. The retardation plate may have an appropriate retardation according to the purpose of use such as, for example, various wavelength plates or those intended for compensation of a viewing angle or the like due to birefringence of a liquid crystal layer, and may have two or more types. A retardation plate may be laminated to control optical characteristics such as retardation.

The elliptically polarizing plate and the reflection type elliptically polarizing plate are obtained by laminating a polarizing plate or a reflection type polarizing plate and a retardation plate in an appropriate combination. Such an elliptically polarizing plate or the like can also be formed by sequentially and separately laminating a (reflection type) polarizing plate and a retardation plate in a manufacturing process of a liquid crystal display device so as to form a combination. An optical member such as a polarizing plate has an advantage that the stability of quality and laminating workability are excellent and the production efficiency of a liquid crystal display device or the like can be improved.

The adhesive layer provided on one side or both sides of the optical base is for bonding other members such as a liquid crystal cell or between optical bases. For its formation, for example, acrylic or silicone, polyester or polyurethane,
An adhesive substance or an adhesive using a suitable polymer such as a polyamide-based, polyether-based, fluorine-based or rubber-based, polyolefin-based, or polyvinyl alcohol-based polymer can be used, and is not particularly limited.

Among them, those which are excellent in optical transparency such as acrylic pressure-sensitive adhesives, exhibit appropriate wettability, cohesiveness and adhesiveness, and are excellent in weather resistance and heat resistance can be preferably used. In addition, prevention of foaming phenomenon and peeling phenomenon due to moisture absorption,
An adhesive layer having a low moisture absorption rate and excellent heat resistance is preferred from the viewpoints of preventing deterioration of optical properties due to a difference in thermal expansion and the like, prevention of warpage of the liquid crystal cell, and formation of a liquid crystal display device having high quality and excellent durability.

The adhesive layer is made of, for example, natural or synthetic resins, particularly, tackifier resins, glass fibers and glass beads, fillers and pigments made of metal powders and other inorganic powders, coloring agents and oxidizing agents. It may contain an appropriate additive such as an inhibitor which may be added to the adhesive layer. Further, an adhesive layer containing fine particles and exhibiting light diffusibility may be used.

The provision of the adhesive layer on one side or both sides of the optical substrate can be performed by an appropriate method. By the way, as an example,
For example, an adhesive substance or a composition thereof is dissolved or dispersed in a solvent consisting of an appropriate solvent alone or a mixture of appropriate solvents such as toluene and ethyl acetate to prepare an adhesive liquid of about 10 to 40% by weight, which is cast. Examples of the method include a method in which the adhesive layer is directly provided on the optical substrate by an appropriate development method such as a method or a coating method, or a method in which an adhesive layer is formed on a separator according to the above and transferred to the optical substrate. .

The pressure-sensitive adhesive layer may be provided on one side or both sides of the optical substrate as a superposed layer of different compositions or types. When provided on both surfaces, an adhesive layer having a different composition, type, thickness, and the like may be formed on the front and back surfaces of the optical substrate. The thickness of the pressure-sensitive adhesive layer can be appropriately determined depending on the purpose of use, adhesive strength, and the like, and is generally 1 to 500 μm, preferably 5 to 20 μm.
0 μm, especially 10 to 100 μm.

In the present invention, the optical base material and the adhesive layer forming the above-mentioned optical member may be made of, for example, a salicylic acid ester compound, a benzophenol compound, a benzotriazole compound, a cyanoacrylate compound, a nickel complex salt compound, or the like. A material having an ultraviolet absorbing ability by an appropriate method such as a method of treating with an ultraviolet absorber may be used.

The laminate to be processed according to the present invention has at least one optical base material and at least one adhesive layer. Therefore, a laminate having two or more optical substrates or / and two or more adhesive layers may be used. When the adhesive layer of the laminate is exposed, it is preferable to temporarily attach the separator 3 or the like as shown in the figure to protect it from contamination or the like.
The separator can be obtained, for example, as a film coated with an appropriate release agent such as a silicone-based, long-chain alkyl-based, or fluorine-based release agent, or as a laminate thereof.

The spray coating is formed on the edge of the adhesive layer in the laminate by stacking a plurality of the laminates and applying a non-adhesive coating to the side surface of the laminate, that is, the surface where the adhesive layer of the laminate is exposed. Is formed by spraying a quick-drying paint for forming a film. Spraying can be performed by a suitable non-contact method such as an ink jet method, a bubble jet method, or an air brush method, that is, the paint can be sprayed onto the adhesive layer in a state of a spray liquid without involving a tool that comes into contact with the adhesive layer such as a brush. It can be performed by an appropriate method.

The components forming the coating film are not particularly limited as long as they form a non-adhesive film. Accordingly, inks used in the above-described ink jet system, bubble jet system, and the like can also be used. Above all, it is preferable to use a solvent which can be formed into a solution with a solvent having a low boiling point such as methyl ethyl ketone and isopropyl alcohol, and which can rapidly form a coating which is dried or hardened to form a film by spray drying. Those that form a film having excellent flexibility are preferable.

Incidentally, specific examples of the coating film forming component include olefin resins such as polyethylene, polypropylene and ethylene-propylene copolymer, polyester resins such as polyethylene terephthalate and polyethylene naphthalate, diallyl phthalate resins and polyurethane resins. , Polyvinyl chloride and polyvinylidene chloride, polyvinyl acetate and ethylene / vinyl acetate copolymer, polyvinyl alcohol and polystyrene, AS resin and ABS resin,
(Meth) acrylic resins, polyamides, cellulose resins, polysulfones, polyethersulfones, polycarbonates, thermoplastic resins such as acetal resins and polyphenylene oxide.

The above-mentioned thermoplastic resin is also used in a method in which the heated melt is sprayed in a non-contact manner on the side surface of the stacked body of the laminate to form a spray coating film on the edge of the adhesive layer. be able to. The spray coating is preferably colorless, transparent, white or black from the viewpoint of suppressing optical effects, but is not limited thereto.

In the above-mentioned coating film forming process, the number of stacked layers to be stacked is arbitrary. The edge of the adhesive layer forming the coating film may be all or part of the opposite side of the rectangular body. In the spraying process, an appropriate edge form such as an edge of an adhesive layer free from contamination by cutting a predetermined surface of the laminate in advance or an edge having a rough surface such as fine irregularities can be used. .

The thickness of the sprayed coating film to be formed can be appropriately determined according to the purpose of preventing the sticking layer from protruding or preventing contamination, but is generally 100 μm or less, especially 0.1 to 50 μm,
In particular, it is 0.5 to 10 μm. The thickness of the spray coating film to be formed can be adjusted by adjusting the amount of the spray liquid.

The spray coating film formed on the edge of the adhesive layer functions as a film for preventing the adhesive layer from protruding or being stained. Further, when the optical member is conveyed on a production or processing line, the end face of the optical member guides the line. It can also function as a prevention film that adheres to the surface to prevent running disturbance, or a prevention film that prevents the end face of the optical member from adhering to a frame wall such as a frame to make replacement difficult.

The optical member according to the present invention can be preferably used for forming various devices such as a liquid crystal display device.
In particular, it can be preferably used for an optical member for precision use in which, for example, contamination of the end face becomes a problem from the viewpoint of the functions described above, or an apparatus formed using an optical member for use on a line.

[0035]

EXAMPLE 1 A polarizing plate comprising a polyvinyl alcohol-based polarizing film having a thickness of 60 .mu.m and a protective film made of triacetyl cellulose having a thickness of 80 .mu.m bonded to both surfaces of a polarizing film having a thickness of 20 .mu.m via a polyvinyl alcohol-based adhesive layer. On one side, a laminate was obtained in which an acrylic pressure-sensitive adhesive layer provided on the separator and having a thickness of 20 μm was adhered together with the separator.

Next, the above-mentioned laminated body was punched into an 11-inch size, and 100 sheets were piled up, held by a vice-shaped jig from above and below, and sprayed with a fast-curing paint on the side surface by an ink jet method. Thus, an optical substrate having a spray coating film having a thickness of about 2 μm on the edge of the adhesive layer was obtained.

Comparative Example An optical base material was obtained in the same manner as in Example 1 except that a coating film was formed by applying a fast-curing paint to the side surface of the stacked body via a brush instead of the spray method.

Evaluation Test For the optical members obtained in Example 1 and Comparative Example, an adhesive feeling at the edges, adhesion contamination due to intrusion of paint between layers of the stacked body,
Also, the presence or absence of coating film formation unevenness at the edges was examined. The results are shown in the following table.

Adhesive feeling Adhesion contamination Uneven formation Example 1 No No No Comparative example No Yes Yes

[Brief description of the drawings]

FIG. 1 is a perspective sectional view of an embodiment.

[Description of Signs] 1: Optical substrate 2: Adhesive layer 3: Separator 4: Spray coating

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Tominari Araki 1-1-2 Shimohozumi, Ibaraki-shi, Osaka Nitto Denko Corporation (72) Inventor Yuji 1-1 Shimohozumi, Ibaraki-shi, Osaka No. 2 Inside Nitto Denko Corporation (72) Inventor Kazuyoshi Seki 1-1-2 Shimohozumi, Ibaraki-shi, Osaka Prefecture In-house Nitto Denko Corporation (72) Honorable Masada 1-chome Shimohozumi, Ibaraki-shi, Osaka 1-2-2 Nitto Denko Corporation (72) Inventor Toyoharu Takao 1-2-2 Shimohozumi, Ibaraki-shi, Osaka F-term (reference) 2H049 BA02 BA06 BB13 BB51 BB54 BB62 BB63 BC14 BC22 4F100 AJ06 AK21 AK21G AK25G BA02 BA44 CB05B CC00 DB15B EC18 EH46B EH61B EJ91 JL13B JL14 JN00A JN10

Claims (3)

[Claims] 1. An optical member comprising a laminate having at least an optical base material and an adhesive layer, wherein the laminate has a non-adhesive spray coating on an edge of the adhesive layer. 2. The optical member according to claim 1, wherein the optical substrate is one or more of a polarizing plate and a retardation plate. 3. An edge of the adhesive layer in the laminate by spraying a quick-drying paint for forming a non-adhesive coating film on at least the side surfaces of the plurality of laminates of the laminate having the optical substrate and the adhesive layer. A method for producing an optical member, comprising forming a non-adhesive spray coating on a side.