JP2002303730A - Optical member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical member having no trouble with a blocking phenomenon and exhibiting excellent release property and further producing no pasty stain or no paste dropping caused by an adhesive layer. SOLUTION: The optical member comprises an adhesive optical film consisting of an optical film with the adhesive layer on one of its surfaces. A releasing film is attached to the adhesive layer and a protective film with an attached adhesive is attached to the other surface of the optical film. The optical member is characterized by making at least one out of the releasing film and the protective film with the attached adhesive have a size overrunning a size of the adhesive optical film on a part or the whole of the peripheral part of the adhesive optical film.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical member having an adhesive optical film having an adhesive layer on one surface of an optical film and a release sheet and / or a protective film with an adhesive provided on the other surface. . Examples of the optical film constituting the optical member include a polarizing film, a retardation film, an optical compensation film, a brightness enhancement film, an antiglare sheet or a laminate of a plurality of these, and the optical film is an adhesive optical film. Used for liquid crystal display devices and the like.

[0002]

2. Description of the Related Art In a liquid crystal display, it is indispensable to arrange polarizing elements on both sides of a glass substrate forming the outermost surface of a liquid crystal panel in view of an image forming method. Affixed to the surface. In addition to the polarizing film on the outermost surface of the liquid crystal panel,
Various optical elements have been used to improve the display quality of a display. For example, a retardation film for preventing coloration, a viewing angle widening film for improving the viewing angle of a liquid crystal display, and a brightness enhancement film for increasing the contrast of the display are used. These films are collectively called optical films.

When the optical film is attached to the outermost surface of a liquid crystal panel, an adhesive is usually used. In addition, since the optical film can be instantly fixed to the outermost surface of the liquid crystal panel and does not require a drying step for fixing the optical film, the adhesive is provided with an adhesive layer on one side of the optical film in advance. It is provided as.
That is, an adhesive optical film is generally used for attaching the optical film to the outermost surface of the liquid crystal panel. A release sheet is provided on the adhesive layer of the adhesive optical film for protection until the optical film is attached to the liquid crystal panel. On the other hand, a protective film is adhered to the optical film surface serving as the liquid crystal display surface to protect the optical film surface until the liquid crystal cell is assembled.

As described above, the pressure-sensitive adhesive optical film is used as an optical member having a release sheet attached to the surface of the adhesive layer and a protective film provided on the other surface. The optical member is cut into a shape and a size corresponding to various uses according to various uses. Conventionally, in such an optical member, as shown in FIG. 4, an adhesive optical film comprising an optical film 1 and an adhesive layer 2 thereof, a release sheet 3, and a protective film 4 with an adhesive are all cut to the same dimensions. Was.

The optical members are usually stored by laminating them. However, when the optical members have the same dimensions, the adhesion between the optical members becomes strong, and there is a problem that the optical members are blocked in a stacked state. Therefore, when removing the optical members one by one from the stacked state when attaching the panel, the optical members stacked below may be lifted together (stacking), which hinders continuous production. It may come out. Also, the release sheet, the protective film with the adhesive is finally peeled from the adhesive optical film, but if all of the optical members are the same size,
There is also a problem that the peeling becomes heavy (heavy peeling) and it cannot be peeled. Furthermore, since the adhesive layer is exposed on the cut side surface of the optical member cut to the same size, adhesive lamination or adhesive deficiency in which the adhesive sticks out of the adhesive layer during lamination or transport of the optical member is eliminated. May occur.

[0006]

SUMMARY OF THE INVENTION The present invention relates to an optical film having an adhesive film having an adhesive layer on one surface of an optical film and a release sheet and / or a protective film with an adhesive provided on the other surface. An object of the present invention is to provide an optical member that is a member and has no blocking property and good releasability. Still another object of the present invention is to provide an optical member free from glue stains and glue defects due to an adhesive layer.

[0007]

The present inventors have made intensive studies to solve the above-mentioned problems, and as a result, have found that the above-mentioned object can be achieved by the following optical members, and have completed the present invention.

That is, the present invention relates to an adhesive optical film having an adhesive layer on one surface of an optical film, wherein a release sheet is provided on the adhesive layer, or an adhesive is provided on the other surface of the optical film. An optical member provided with a protective film, wherein the size of the release sheet or the protective film with an adhesive provided is the size of the adhesive optical film in part or all of the peripheral portion of the adhesive optical film. And an optical member characterized by:

In another aspect of the present invention, a release sheet is attached to the adhesive layer of the optical film having an adhesive layer on one surface of the optical film, and an adhesive is provided on the other surface of the optical film. An optical member provided with a protective film, wherein the size of at least one of the release sheet and the protective film with an adhesive is a part or all of the periphery of the adhesive optical film. An optical member characterized by exceeding the size.

[0010] In the optical member of the present invention, the size of the release sheet provided for protecting the adhesive layer and / or the protective film provided with the adhesive provided for protecting the surface of the optical film is smaller than that of the adhesive optical film. The size exceeds the size, and the end portions of the pressure-sensitive adhesive optical film and the release sheet and / or the protective film with a pressure-sensitive adhesive are not at the same position. For this reason, even when the optical members are stacked, the adhesion is weakened and the blocking is suppressed, and when the optical members are attached to the panel, the overlapping of the optical members stacked can be prevented. Further, since the size of the release sheet and / or the protective film with the adhesive is larger than the size of the adhesive optical film, the surface adhesion is weakened, the releasability is good, and there is no problem of heavy peeling. Furthermore, when the release sheet is oversized, glue stain and glue loss due to exposure on the cut side surface of the adhesive layer are suppressed, and good surface stain prevention is exhibited. In order to prevent the surface dirt from being prevented by the adhesive layer, it is preferable to make the release sheet oversized for the adhesive optical film at the entire periphery of the adhesive optical film.

In the optical member, the size of the release sheet and / or the protective film with an adhesive exceeding the size of the pressure-sensitive adhesive optical film may be partially or entirely at the periphery of the pressure-sensitive adhesive optical film. Preferably, the size of the film exceeds 0.05 to 5 mm width.

The size and shape of the pressure-sensitive adhesive optical film are determined according to various uses, and the excess size of the release sheet and the protective film with a pressure-sensitive adhesive are also appropriately determined according to various uses. In order to effectively exhibit the blocking property, the releasability, and the surface dirt prevention property, the release sheet, the excess size of the protective film with an adhesive is 0.05 mm or more,
Further, it is preferable that the thickness be 0.5 mm or more. on the other hand,
It is preferable that the release sheet and the protective film with an adhesive have an excess size of 5 mm or less, more preferably 1 mm or less, in terms of preventing adhesion and settling foreign matter and turning over exposed portions due to product handling.

[0013] In the optical member, the adhesive optical film is square, and on at least two sides of the square, a release sheet and / or a protective film with an adhesive that exceeds the size of the adhesive optical film is formed of an adhesive. In a preferred embodiment, the size of the optical film is exceeded.

An adhesive optical film used for a liquid crystal display layer or the like is usually formed in a square shape in accordance with the liquid crystal display layer or the like.
In this case, the release sheet and the protective film with the adhesive may be in excess of at least one part (for example, one side) of the square, but may have excess size in two sides when the liquid crystal panel bonding line is transported. Is preferred from the viewpoint of preventing glue loss in the above. The two sides are preferably provided on the opposite side in that they are compatible with the transport line. Release sheet,
The protective film with an adhesive has the same effect as the two sides even when the three sides of the square are oversized. When the size is excessive on the four sides, glue stains can be suppressed to a minimum, and glue marks can be prevented from remaining on the optical film laminate due to the overflowing glue.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an optical member according to the present invention will be described with reference to the drawings. The optical member of the present invention is shown, for example, in FIGS. 1 to 3 show a release sheet 3 attached to an adhesive layer 2 of an adhesive type optical film comprising an optical film 1 and an adhesive layer 2 thereof, and an adhesive film on the surface of the optical film 1 where the adhesive layer 2 is not provided. FIG. 3 is a side view of an optical member provided with a protective film with an agent 4. 1 to 3 illustrate the case where the release sheet 3 and the protective film 4 with an adhesive are attached, the release sheet 3 and the protective film 4 with an adhesive exceed the size of the adhesive optical film. The object may be provided only on one of them.

FIG. 1 shows an example in which the size of the release sheet 3 exceeds the size of the adhesive optical film, and FIG. 2 shows an example in which the size of the protective film 4 with the adhesive exceeds the size of the adhesive optical film. FIG. 3 is an example in which the size of both the release sheet 3 and the protective film 4 with an adhesive exceeds the size of the adhesive optical film. FIG.
In FIG. 3 to FIG. 3, a is the excess size of the release sheet 3 and / or the protective film 4 with an adhesive, and is an example having the excess size on at least two opposite sides.

FIG. 5 is an example of a top view of FIG. 1, in which the release sheet 3 has an excess size a at four sides. In addition,
The excess size a is determined according to various uses in which the pressure-sensitive adhesive optical film is used.
It is preferably about mm. In particular, the shape of the pressure-sensitive adhesive optical film is rectangular, and the length of one side is 20 to
When the length is about 500 mm, the excess size is preferable. Note that the excess size a may or may not have the same width in all cases.

The optical member of the present invention comprises a release sheet and / or
Alternatively, the manufacturing method is not particularly limited as long as the size of the protective film with an adhesive exceeds the size of the adhesive type optical film. For example, an optical member is punched using a Thomson press blade shown in FIG. It can be done by doing. Conventionally, as a Thomson press blade die, as shown in FIG. 7, a wooden die 10 having only an outer shape cutting blade 11 was used. Therefore, all the constituent materials of the obtained optical member were cut to the same dimensions as shown in FIG. On the other hand, in the production of the optical member of the present invention, FIG.
As shown in FIG.
2 is used. By appropriately adjusting the installation position of the inner shape punching blade 12, the excess size and the excess size portion of the release sheet and / or the protective film with an adhesive can be determined. According to the Thomson press cutter of FIG. 6, the optical member of the present invention having an excess size on the entire periphery (all four sides) can be obtained. A in FIG.
Is a width for adjusting the excess size, and b is such that they are not cut by a punching stroke (distance) of a Thomson press in accordance with the thickness of the release sheet and / or the protective film with an adhesive which becomes the excess size. It is adjusted to.

The optical member shown in FIG. 1 is mounted on a Thomson press blade die shown in FIG. 6 so that the optical member before punching is placed so that the release sheet 3 faces upward. It is obtained by removing the protective film 4 with the adhesive and the adhesive optical film between the inner shape cutting blades 12. The optical member shown in FIG. 2 is installed in the Thomson press blade mold shown in FIG. 6 so that the protective film 4 with the adhesive faces upward before punching. It can be obtained by removing the release sheet 3 and the adhesive optical film between the punching blades 12. Although FIG. 2 illustrates a case where the protective film with an adhesive (including the adhesive layer of the protective film) has an excessive size, only the protective film of the protective film with an adhesive has an excessive size. It can also be cut into pieces. Further, the optical member shown in FIG. 3 is obtained by peeling the protective film 4 with an adhesive from the optical member shown in FIG. 1, manufacturing it separately, and replacing it with a protective film 4 with a larger size than the optical film 1. .

The materials constituting the optical member of the present invention are as follows.

(Optical Film) As the optical film 1, a film used for forming a liquid crystal display device or the like is used, and the type thereof is not particularly limited. For example, examples of the optical film include a polarizing film, an elliptically polarizing film, a polarizing film having an optical compensation function, a polarizing film having a viewing angle expanding function, a polarizing film having a brightness improving function, and the like. These are retardation films, polarizing films,
An optical compensation film, a brightness enhancement film, an antiglare sheet, and the like are laminated.

As the polarizer constituting the polarizing film,
There is no particular limitation, and various types can be used. Examples of the polarizer include dichroic dyes such as iodine and dichroic dyes on hydrophilic polymer films such as polyvinyl alcohol-based films, partially formalized polyvinyl alcohol-based films, and ethylene / vinyl acetate copolymer-based partially saponified films. Examples thereof include a film obtained by adsorbing a substance and stretched, and a polyene-based oriented film such as a dehydrated product of polyvinyl alcohol and a dehydrochlorinated product of polyvinyl chloride. Although the thickness of the polarizer is not particularly limited, it is generally about 5 to 80 μm.

On one or both sides of the polarizer, a transparent protective layer can be provided as a coating layer of a polymer or a laminate layer of a film for the purpose of water resistance or the like. As the transparent polymer or film material for forming the transparent protective layer, an appropriate transparent material can be used, but a material having excellent transparency, mechanical strength, heat stability, moisture barrier property and the like is preferably used. Although the thickness of the transparent protective layer is not particularly limited, it is generally about 10 to 300 μm.

Materials for forming the transparent protective layer include:
For example, polyester polymers such as polyethylene terephthalate and polyethylene naphthalate, cellulosic polymers such as cellulose diacetate and cellulose triacetate, acrylic polymers such as polymethyl methacrylate, and styrene such as polystyrene and acrylonitrile-styrene copolymer (AS resin) Polymers, polycarbonate polymers and the like. In addition, polyethylene, polypropylene, polyolefin having a cyclo- or norbornene structure, polyolefin polymers such as ethylene-propylene copolymer, vinyl chloride polymers, amide polymers such as nylon and aromatic polyamide, imide polymers, and sulfone polymers , Polyether sulfone polymer, polyether ether ketone polymer, polyphenylene sulfide polymer, vinyl alcohol polymer, vinylidene chloride polymer, vinyl butyral polymer, arylate polymer, polyoxymethylene polymer, epoxy polymer, or the above Blends of polymers and the like are also examples of the polymer forming the transparent protective layer.

Examples of the retardation film include a birefringent film and a liquid crystal polymer film obtained by uniaxially or biaxially stretching a polymer material. Although the thickness of the retardation film is not particularly limited, it is generally about 20 to 150 μm. The retardation plate can be formed as a superimposed body of two or more stretched films to control the optical properties such as retardation, etc. It can also be used as an elliptically polarizing film laminated with a polarizing film to compensate for a phase difference or the like.

Examples of the polymer material include polyvinyl alcohol, polyvinyl butyral, polymethyl vinyl ether, polyhydroxyethyl acrylate, hydroxyethyl cellulose, hydroxypropyl cellulose, methyl cellulose, polycarbonate, polyarylate, polysulfone, polyethylene terephthalate, polyethylene naphthalate, and polyethylene naphthalate. Ether sulfone, polyphenylene sulfide, polyphenylene oxide,
Examples include polyallyl sulfone, polyvinyl alcohol, polyamide, polyimide, polyolefin, polyvinyl chloride, cellulose polymers, and various binary and ternary copolymers, graft copolymers, and blends thereof. These polymer materials become oriented products (stretched films) by stretching or the like.

Examples of the liquid crystalline polymer include various types of main chain type and side chain type in which a conjugated linear atomic group (mesogen) imparting liquid crystal orientation is introduced into the main chain or side chain of the polymer. And so on. Specific examples of the main chain type liquid crystalline polymer include a structure in which a mesogen group is bonded by a spacer portion that imparts flexibility, such as a nematic-oriented polyester-based liquid crystalline polymer, a discotic polymer, and a cholesteric polymer. . Specific examples of the side-chain type liquid crystalline polymer include polysiloxane, polyacrylate, polymethacrylate or polymalonate having a main chain skeleton, and a paraffin-imparting paraffin having a conjugated atomic group as a side chain. And those having a mesogen moiety composed of a substituted cyclic compound unit. These liquid crystalline polymers are prepared by, for example, rubbing the surface of a thin film of polyimide or polyvinyl alcohol formed on a glass plate, or applying a liquid crystalline polymer solution on an alignment-treated surface such as obliquely deposited silicon oxide. It is performed by developing and heat-treating.

The polarizing film and the retardation film may be laminated and used, and may be a reflection type polarizing film, a semi-transmissive layer type polarizing film, a polarized light separating polarizing film or the like. In addition, the above-described optical films can be used as optical compensation films and other various viewing angle widening films, and examples of the optical films include brightness enhancement films and the like. Further, the polarizing film may be provided with a reflection layer having a fine uneven structure on the surface to form an antiglare sheet.

(Adhesive Layer) Examples of the adhesive for forming the adhesive layer 2 include rubber-based adhesives, acrylic-based adhesives, and silicone-based adhesives. Is preferred. Further, the pressure-sensitive adhesive may contain a crosslinking agent such as a polyisocyanate compound, a polyamine compound, a melamine resin, a urea resin, and an epoxy resin. Further, the pressure-sensitive adhesive, if necessary, a tackifier, a plasticizer, a filler, an antioxidant, an ultraviolet absorber, a silane coupling agent, etc., as appropriate within a range not departing from the object of the present invention. Can also be used.

The method of forming the pressure-sensitive adhesive layer 2 is not particularly limited. A method of applying a pressure-sensitive adhesive (solution) to the optical film 1 and drying the same, and transferring the release sheet 4 provided with the pressure-sensitive adhesive layer 2 to the optical film 1. Method and the like. The thickness of the adhesive layer 2 (dry film thickness) is not particularly limited, but is preferably about 10 to 40 μm.

(Release Sheet) Examples of the constituent material of the release sheet 3 include paper, synthetic resin films such as polyethylene, polypropylene, and polyethylene terephthalate. The surface of the release sheet 3 may be subjected to a release treatment such as a silicone treatment, a long-chain alkyl treatment, or a fluorine treatment, if necessary, in order to enhance the releasability from the adhesive layer 2.

(Protective Film with Adhesive) The protective film with adhesive 4 is obtained by forming an adhesive layer 4 b on a base film 4 a, and the adhesive layer 4 b is adhered to the surface of the optical film 1. As the base film 4a, for example,
A biaxially stretched film such as polypropylene or polyester can be preferably used. The thickness of the plastic film serving as the base film 4a is not particularly limited, but is preferably about 10 to 200 μm,
Particularly, 20 to 50 μm is preferable.

As the pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer 4b formed on one side of the base film 4a, any of acrylic, synthetic rubber and rubber-based pressure-sensitive adhesives can be used. Acrylic pressure-sensitive adhesives that are easy to control are preferred. The pressure-sensitive adhesive can contain a crosslinking agent such as a polyisocyanate compound, a polyamine compound, a melamine resin, a urea resin, or an epoxy resin as a crosslinking agent. Further, the pressure-sensitive adhesive, if necessary,
A tackifier, a plasticizer, a filler, an antioxidant, an ultraviolet absorber, a silane coupling agent, and the like can be appropriately used. The thickness (dry film thickness) of the adhesive layer 4b is not particularly limited, but is usually about 5 to 50 μm, preferably 5 to 30 μm.
μm.

[Brief description of the drawings]

FIG. 1 is a side view of an example of an optical member of the present invention.

FIG. 2 is a side view of an example of the optical member of the present invention.

FIG. 3 is a side view of an example of the optical member of the present invention.

FIG. 4 is a side view of a conventional optical member.

FIG. 5 is a top view of the optical member of FIG. 1;

FIG. 6 is a schematic view of a Thomson press blade used for manufacturing the optical member of the present invention.

FIG. 7 is a schematic view of a conventional Thompson press blade used for manufacturing an optical member.

[Explanation of symbols]

 Reference Signs List 1 optical film 2 adhesive layer 3 release sheet 4 protective film with adhesive a excess size

 ──────────────────────────────────────────────────続 き Continued on the front page F-term (reference) 2H049 BA02 BA06 BA25 BA26 BA27 BB23 BB26 BB27 BB28 BB33 BB43 BB51 BB54 BB62 BC03 BC14 BC22 2H091 FA08X FA08Z FA11X FA11Z FA50X FA50Z FB02 FB12 FC16 AT19 FB15 AT03A00 AT00 BA04 BA07 BA10A BA10C DG10 GB41 JL00 JL13B JL14C

Claims (4)

[Claims] 1. An adhesive optical film having an adhesive layer on one surface of an optical film, wherein a release sheet is attached to the adhesive layer, or a protective film with an adhesive is attached to the other surface of the optical film. In the optical member, the size of the release sheet or the protective film with the adhesive attached is larger than the size of the adhesive optical film in part or all of the peripheral portion of the adhesive optical film. An optical member characterized by the above-mentioned. 2. A pressure-sensitive adhesive optical film having an adhesive layer on one surface of an optical film, a release sheet attached to the adhesive layer, and a protective film with an adhesive on the other surface of the optical film. An attached optical member, wherein the size of at least one of the release sheet and the protective film with an adhesive exceeds the size of the adhesive optical film in part or all of the periphery of the adhesive optical film. An optical member, comprising: 3. The size of a release sheet and / or a protective film with a pressure-sensitive adhesive film that exceeds the size of the pressure-sensitive adhesive optical film is partially or entirely at the periphery of the pressure-sensitive adhesive optical film. Is 0.05
The optical member according to claim 1, wherein the width exceeds 5 mm. 4. The pressure-sensitive adhesive optical film is square, and at least two sides of the square have a release sheet and / or a protective film with a pressure-sensitive adhesive that exceeds the size of the pressure-sensitive adhesive optical film, The optical member according to claim 1, wherein the size of the optical member is larger than the size.