WO2011001834A1

WO2011001834A1 - Roll of optical sheet material and continuous manufacturing method of liquid crystal display device

Info

Publication number: WO2011001834A1
Application number: PCT/JP2010/060324
Authority: WO
Inventors: 浩平矢野; 武田　健太郎; 悠杉本
Original assignee: 日東電工株式会社
Priority date: 2009-06-29
Filing date: 2010-06-18
Publication date: 2011-01-06
Also published as: TW201109175A; JP2011008195A

Abstract

Disclosed is a roll of an optical sheet material that is not prone to problems of cut surfaces sticking, and preferably, that is not prone to wrinkles (orange peel), denting, etc., when shipped or stored; also disclosed is a method for manufacturing a liquid crystal display device using the roll of optical sheet material. The roll of an optical sheet material is characterized in that the aforementioned optical sheet material has a releasable carrier film on at least one surface of the optical film with an adhesive layer interposed therebetween; the aforementioned adhesive layer comprises an acrylic (co-)polymer having a storage elastic modulus of 0.9-1.2 MPa when subjected to a shear strain (800µm thickness, 0.1% dynamic strain) at a frequency of 10 Hz at 23°C; the elongation at break in tensile tests is 500-2000%; and, when the adhesive layer is pressurized in one reciprocating movement with a 2 kg roller on a smooth stainless steel (SUS304: Koei Industry Co., Ltd.) surface, the adhesion force is 3-15 N / 25mm when peeled away at 180° at a peeling rate of 300 mm / minute one minute after adhesion.

Description

Optical sheet member wound body and liquid crystal display device continuous manufacturing method

The present invention relates to a wound body of an optical sheet member having a releasable carrier film via an adhesive layer on at least one surface of an optical film, and a continuous manufacturing method of a liquid crystal display device using the same.

Conventionally, optical film manufacturers continuously manufacture strip-shaped products having optical film members by winding them around a roll. Then, when delivering the optical film member to the liquid crystal panel processing manufacturer that assembles the optical film member and the optical display unit, the roll-shaped product is punched into a predetermined size, and the sheet-like products after punching are stacked on several sheets. Packed and delivered.

However, the above method has the following problems. That is, when bonding each piece of optical film to the liquid crystal cell, it is necessary to set each piece in the apparatus and peel off the release film, which increases the process time and necessitates packing materials. The dismantling work is also complicated.

In order to solve such problems, a roll on which a belt-like sheet product having an optical film is wound is delivered to a liquid crystal panel processing manufacturer, and roll supply, defect inspection, cutting processing, and bonding to a liquid crystal display device are performed. A manufacturing method performed in a series of steps has been proposed (for example, Patent Document 1). Moreover, about the cutting process, the half cut which cut | disconnects an optical film and an adhesive layer, leaving a carrier film is employ | adopted.

International Publication WO2008-047712

However, in the conventional single wafer type, after punching the roll-shaped optical film, the end face is cut to remove the adhesive adhesion on the cut surface, but as described above, it is directly from the raw roll. In the method of pasting, since end surface processing cannot be performed, there was a problem that defects due to adhesion of glue on the cut surface increased. Furthermore, in the manufacturing method as described above, when the roll is delivered to a liquid crystal panel processing manufacturer or stored for a long time after delivery, the roll of the roll may cause wrinkles in the pressure-sensitive adhesive layer or the pressure-sensitive adhesive layer. Even if small foreign substances are included, it is easy to generate imprints called dents due to the influence of tightening of the roll, and if the optical member has a surface treatment, the shape of the surface treatment is transferred to the adhesive layer, etc. Defects of the adhesive layer tend to occur frequently.

Accordingly, an object of the present invention is that the problem of adhesive adhesion on the cut surface is less likely to occur. Preferably, the optical sheet member is less likely to cause creases (yuzu skin), dents or the like during roll shipment or storage. An object of the present invention is to provide a wound body and a method for manufacturing a liquid crystal display device using the same.

As a result of intensive studies to solve the above problems, the present inventors have found that the above object can be achieved by using a pressure-sensitive adhesive layer having predetermined physical properties, and have completed the present invention.

That is, the wound body of the optical sheet member of the present invention is a wound body of the optical sheet member, and the optical sheet member has a releasable carrier film on at least one surface of the optical film via the adhesive layer. The pressure-sensitive adhesive layer is made of an acrylic (co) polymer and has a storage elastic modulus of 0.9 to 0.9 when shear strain (thickness 800 μm, dynamic strain 0.1%) is applied at 23 ° C. and a frequency of 10 Hz. 1.2 MPa, the elongation at break in the tensile test is 500 to 2000%, and the surface of smooth stainless steel (SUS304: manufactured by Guangei Industry Co., Ltd.) was reciprocated once using a 2 kg roller, and 1 minute after pasting The adhesive strength when peeled at 180 ° at a peeling speed of 300 mm / min is 3 to 15 N / 25 mm.

In the wound body of the optical sheet member of the present invention, if the storage elastic modulus is too low, adhesion of the paste to the cut surface is increased and storage stability is deteriorated. If the storage elastic modulus is too high, peeling is likely to occur in the wet heat test. Become. On the other hand, if the elongation at break is too small, peeling tends to occur in the wet heat test, and if the elongation at break is too large, adhesion of glue to the cut surface increases and storage stability is deteriorated. Furthermore, if the adhesive force is too large, adhesive adhesion to the cut surface increases and storage stability is deteriorated. If the adhesive force is too small, peeling easily occurs in the wet heat test. As a result, according to the wound body of the optical sheet member of the present invention, it is difficult to cause wrinkles, distorted skin, dents, etc. during roll shipment and storage, and also to prevent the problem of glue adhesion on the cut surface. A wound body of a sheet member can be provided.

In the above, it is preferable that the pressure-sensitive adhesive layer has a gel fraction of 70 to 90% and a holding power (H _A ) at 23 ° C. measured by the following evaluation method of 200 μm or less. Here, the holding force (H _A ) is a 10 mm × 30 mm optical film with an upper end of 10 mm × 10 mm attached to an alkali-free glass plate (Corning 1737, thickness 0.7 mm) with a pressing force of 2 Kg through an adhesive layer. And then autoclaved for 15 minutes at 50 ° C. and 5 atmospheres, left at room temperature for 1 hour, and then loaded with a load of 500 g on the lower end of the optical film and left for 1 hour. It represents the width of deviation from the front and rear glass plates.

When the gel fraction is within the above range, adhesive adhesion to the cut surface can be further reduced, and peeling in the wet heat test can be made difficult to occur. Further, when the holding force (H _A ) is within the above range, adhesion of the glue to the cut surface can be further reduced, and the storability can be further improved.

The releasable carrier film is preferably made of a polyester base material. When a polyester-based substrate is used, compared with other resin films, the defects of the film are transferred to the pressure-sensitive adhesive layer, and so-called fish eyes that hinder the determination of defects of the optical film are less likely to occur.

On the other hand, the continuous manufacturing method of the liquid crystal display device of the present invention includes a step of feeding the optical sheet member from the wound body of the optical sheet member according to any one of the above, and the releasing property at a predetermined interval between the fed optical sheet member. A step of cutting the optical film and the pressure-sensitive adhesive layer while leaving the carrier film, and a step of bonding the cut optical film piece to the liquid crystal cell via the pressure-sensitive adhesive layer.

According to the continuous manufacturing method of the liquid crystal display device of the present invention, the roll of the optical sheet member having the above-described effects is used. It is possible to provide a continuous manufacturing method of a liquid crystal display device that can prevent the half-cut portion from being lifted off from the carrier film and hardly cause the problem of adhesive adhesion on the cut surface.

Process drawing which shows an example of the continuous manufacturing method of the liquid crystal display device of this invention

The wound body of the optical sheet member of the present invention is a wound body in which the optical sheet member is wound, and the optical sheet member in the wound body is releasable via an adhesive layer on at least one surface of the optical film. Have a carrier film. Any optical film can be used as long as it is bonded to a liquid crystal cell. For example, a polarizing plate having a transparent protective film on one or both sides of a polarizer can be mentioned. Moreover, what laminated | stacked the retardation film and the other optical compensation film suitably with respect to the polarizer or the polarizing plate may be used.

The pressure-sensitive adhesive layer is made of an acrylic (co) polymer, and has a storage elastic modulus of 0.9 to 1 when a shear strain (thickness 800 μm, dynamic strain 0.1%) is applied at 23 ° C. and a frequency of 10 Hz. 2 MPa, preferably 0.95 to 1.1 MPa. By setting it as such a range, peeling in a wet heat test can be prevented, making the cutting property of an adhesive favorable.

Although it is not clear why the adhesive has good cutting properties by controlling the storage elastic modulus at a frequency of 10 Hz, the deformation speed when the adhesive is cut and deformed is comparable to the deformation speed at a frequency of 10 Hz. This is presumed to be because of this. When the storage elastic modulus is low, the storage property such as the occurrence of dents is deteriorated, and the cutting property of the pressure-sensitive adhesive is deteriorated, and the adhesive state of the cut surface is likely to occur. If the storage elastic modulus is low, peeling in the wet heat test tends to occur.

In the present invention, in order to control the storage elastic modulus, the storage elastic modulus can be controlled by appropriately changing the monomer type of the acrylic polymer, the blending ratio of the crosslinking agent used in the pressure-sensitive adhesive, and the type of the crosslinking agent. For example, when the blending ratio of the crosslinking agent is increased, the storage elastic modulus is increased. Conversely, when the blending ratio of the crosslinking agent is decreased, the storage elastic modulus is decreased.

Also, the elongation at break in the tensile test of the pressure-sensitive adhesive layer is 500 to 2000%, preferably 600 to 1500%. If the elongation at break is too small, peeling tends to occur in the wet heat test, and if the elongation at break is too large, adhesion of glue to the cut surface increases, resulting in poor storage properties. That is, when the elongation at break exceeds a certain value, the glue is pulled and attached to the blade, and the adhesion of the glue to the cut surface tends to increase.

The method for measuring elongation at break was that the pressure-sensitive adhesive layer was formed into a cylindrical shape having a cross-sectional area of 2 mm ² and a length of 30 mm, and this molded product was measured between the chucks using a tensile tester at 23 ° C. and 50% RH. A tensile test is performed at a distance of 10 mm and a pulling speed of 300 mm / min. The elongation at break represents the elongation when the test piece broke in this tensile test. “Elongation at break” (%) = (“Length of test piece at break” − “Initial length (10 mm)”) / “ It is calculated by “initial length (10 mm)” × 100.

The elongation at break can be controlled by appropriately changing the blending ratio of the crosslinking agent used in the pressure-sensitive adhesive and the type of the crosslinking agent, or by appropriately changing the blending ratio and type of the monomer used in the pressure-sensitive adhesive. For example, if the blending ratio of the cross-linking agent is increased, the elongation at break decreases, and conversely, if the blending ratio of the cross-linking agent is decreased, the elongation at break increases.

The adhesive strength of the pressure-sensitive adhesive layer is 3 to 15 N / 25 mm, preferably 3 to 13 N / 25 mm. If the adhesive strength is too small, peeling easily occurs in the wet heat test, and if the adhesive strength is too large, adhesive adhesion to the cut surface increases and storage stability is deteriorated. In other words, the cutting blade is generally a metal, and when the cutting blade enters, if the adhesive force is too high, the adhesive force between the glue and the cutting blade increases and the glue tends to adhere. By evaluating the adhesive force after 1 minute and controlling the value within a certain range, the problem of adhesive adhesion to the cut surface can be improved.

Here, the adhesive force was applied to a smooth stainless steel (SUS304: Guangei Industry Co., Ltd.) surface by reciprocating once using a 2 kg roller, and peeled off at 180 ° at a peeling speed of 300 mm / min one minute after being applied. The adhesive strength is shown.

The adhesive strength of the pressure-sensitive adhesive layer can be controlled by appropriately changing the blending ratio and type of the monomer used in the pressure-sensitive adhesive, or by appropriately changing the blending ratio of the crosslinking agent and the type of the crosslinking agent. For example, when the blending ratio of the acrylic acid monomer is increased, the adhesive force is increased, and when the blending ratio of the acrylic acid monomer is decreased, the adhesive force is decreased.

The gel fraction of the pressure-sensitive adhesive layer is preferably 70 to 90%, more preferably 73 to 87%. If the gel fraction is less than this range, even small foreign matter contained in the adhesive layer will tend to generate imprints called dents due to the influence of roll tightening, and the wound body will be stored for a long time. Wrinkles (yuzu skin) of the pressure-sensitive adhesive layer are likely to occur. When the gel fraction is larger than this range, peeling is likely to occur in the wet heat test. Further, controlling the gel fraction within the above range is preferable also in order to suppress a decrease in the appearance yield due to the occurrence of imprints called dents on the optical film. In the present invention, in order to control the gel fraction, it is sufficient to change the blending ratio of the crosslinking agent used in the pressure-sensitive adhesive and the type of the crosslinking agent. In order to increase the gel fraction, the blending ratio of the crosslinking agent should be increased. It is preferable to use a crosslinking agent having a large number of functional groups per weight. The gel fraction is a value measured by the following method.

<Gel fraction>
The polyethylene terephthalate film subjected to silicone treatment was coated with each pressure-sensitive adhesive composition before sample preparation so that the thickness after drying would be the same as in each example, and after coating the same drying conditions (temperature, The pressure-sensitive adhesive layer was formed by curing at a time), and the gel fraction was measured for the pressure-sensitive adhesive layer after being left for 1 hour under conditions of a temperature of 23 ° C. and a humidity of 65% RH. The gel fraction was measured by taking about 0.2 g of the pressure-sensitive adhesive layer and wrapping it in a fluororesin (TEMISH NTF-1122, manufactured by Nitto Denko Corporation) whose weight (Wa) was measured in advance so that the pressure-sensitive adhesive layer would not leak. After binding, the weight (Wb) was measured, and this was immersed in about 40 ml of ethyl acetate at 23 ° C. for 7 days to extract the soluble component. Thereafter, the fluororesin enclosing the pressure-sensitive adhesive layer was taken out, dried on an aluminum cup at 130 ° C. for 2 hours, and the weight (Wc) of the fluororesin enclosing the pressure-sensitive adhesive layer from which soluble components were removed was measured.

From these measured values, the gel fraction (% by weight) of the pressure-sensitive adhesive layer was determined according to the following formula.

Gel fraction (% by weight) = {(Wc−Wa) / (Wb−Wa)} × 100
In addition, the holding force (H _A ) of the pressure-sensitive adhesive layer at 23 ° C. is preferably 200 μm or less, and more preferably 180 μm or less, from the viewpoints of improving storage properties and reducing the problem of adhesive adhesion on the cut surface.

In the present invention, the holding power (H _A ) can be controlled by changing the blending ratio of the crosslinking agent used in the pressure-sensitive adhesive and the type of the crosslinking agent. In order to reduce the value of the holding power (H _A ). It is preferable to increase the blending ratio of the crosslinking agent or use a crosslinking agent having a large number of functional groups per weight.

The releasable carrier film is made of a polymer film that has been subjected to a release treatment if necessary, and also functions as a separator. The thickness of the carrier film is a viewpoint that secures productivity by increasing the ratio of the optical film in the roll while improving the storability, especially the wrinkle generated by the pressure-sensitive adhesive layer when the wound body is stored for a long time. Therefore, 20 to 40 μm is preferable, and 25 to 38 μm is more preferable. If the carrier film is thinner than this range, the storability deteriorates, and if it is thick, it is not preferable from the viewpoint of productivity.

The peel strength of the carrier film is based on the viewpoint of preventing the phenomenon that the cut edge of the optical film is lifted off from the carrier film when the half cut part passes through the roll part. From the viewpoint of peeling the film and performing good bonding, 0.04 to 0.2 N / 50 mm is preferable, and 0.08 to 0.15 N / 50 mm is more preferable. In this invention, in order to control peeling force, it can control by the kind of carrier film. Specifically, it can be controlled by the type and thickness of the silicone coated on the release surface of the carrier film. The peel strength of the carrier film is a value measured by the following method.
<Peeling force>
The optical sheet member was cut to a width of 50 mm, the carrier film was peeled by 90 ° at a peeling rate of 300 mm / min at 23 ° C., and the initial adhesive force was measured. The adhesive strength was measured according to JIS Z 0237.

As the pressure-sensitive adhesive forming the pressure-sensitive adhesive layer, an acrylic (co) polymer is used, but an acrylic (co) polymer containing 80% by weight or more of a (meth) acrylic acid alkyl ester is preferable. An acrylic pressure-sensitive adhesive is preferably used because it is excellent in optical transparency, exhibits appropriate wettability, cohesiveness, and adhesive pressure-sensitive adhesive properties, and is excellent in weather resistance, heat resistance, and the like.

The acrylic pressure-sensitive adhesive uses a (meth) acrylic polymer having a main skeleton of an alkyl (meth) acrylate monomer unit as a base polymer. Alkyl (meth) acrylate refers to alkyl acrylate and / or alkyl methacrylate, and (meth) in the present invention has the same meaning. Examples of the alkyl (meth) acrylate constituting the main skeleton of the (meth) acrylic polymer include linear or branched alkyl groups having about 1 to 18 carbon atoms, preferably 1 to 9 carbon atoms. it can. For example, the alkyl group includes methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, amyl group, hexyl group, cyclohexyl group, heptyl group, 2-ethylhexyl group, isooctyl group, nonyl group, decyl group. Group, isodecyl group, dodecyl group, isomyristyl group, lauryl group, tridecyl group, pentadecyl group, hexadecyl group, heptadecyl group, octadecyl group, and the like. These can be used alone or in combination. These alkyl groups preferably have an average carbon number of 4 to 12.

In the (meth) acrylic polymer, one or more having a polymerizable functional group having an unsaturated double bond such as a (meth) acryloyl group or a vinyl group for the purpose of improving adhesiveness and heat resistance These copolymerizable monomers can be introduced by copolymerization.

Examples of the copolymerizable monomer having a functional group include a hydroxyl group-containing monomer, a carboxyl group-containing monomer, a nitrogen-containing (eg, amino group, amide group, etc.) monomer, and the like.

Examples of the hydroxyl group-containing monomer include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, 8-hydroxyoctyl (meta ) Acrylates, hydroxyalkyl (meth) acrylates such as 10-hydroxydecyl (meth) acrylate, 12-hydroxylauryl (meth) acrylate; (4-hydroxymethylcyclohexyl) -methyl acrylate; polyethylene glycol (meth) acrylate, polypropylene glycol ( And polyalkylene glycol (meth) acrylate such as (meth) acrylate; caprolactone-modified (meth) acrylate and the like. Among these, hydroxyalkyl (meth) acrylate is preferable. The hydroxyl group-containing monomer is preferably used as a copolymerization monomer for building a crosslinking point with an isocyanate-based crosslinking agent.

Examples of the carboxyl group-containing monomer include (meth) acrylic acid, carboxyethyl (meth) acrylate, carboxypentyl (meth) acrylate, itaconic acid, maleic acid, fumaric acid, and crotonic acid. Among these, (meth) acrylic acid, particularly acrylic acid is preferable. The carboxyl group-containing monomer is preferably used as a copolymerization monomer from the viewpoint of durability.

Examples of the nitrogen-containing monomer include N, N-dimethylaminoethyl (meth) acrylamide, N, N-dimethylaminopropyl (meth) acrylamide, N, N-diethylaminoethyl (meth) acrylamide, N, N-diethylaminopropyl ( N, N-dialkylaminoalkyl (meth) acrylamide such as (meth) acrylamide; N, N-dimethylaminoethyl (meth) acrylate, N, N-dimethylaminopropyl (meth) acrylate, N, N-diethylaminoethyl (meth) Examples thereof include tertiary amino group-containing monomers such as acrylate and N, N-dialkylaminoalkyl (meth) acrylate such as N, N-diethylaminopropyl (meth) acryl acrylate. Examples of the nitrogen-containing monomer include maleimide monomers such as maleimide, N-cyclohexylmaleimide, and N-phenylmaleimide; N- (meth) acryloyloxymethylenesuccinimide and N- (meth) acryloyl-6-oxyhexa Succinimide monomers such as methylene succinimide and N- (meth) acryloyl-8-oxyoctamethylene succinimide; (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N, N-diethyl (meth) acrylamide, N, N -Diethylmethacrylamide, N-methyl (meth) acrylamide, N-ethyl (meth) acrylamide, N-hexyl (meth) acrylamide, N-isopropyl (meth) acrylamide, N-methylol (meth) acrylamide, N-substituted amide monomers such as methoxymethyl (meth) acrylamide and N-butoxymethyl (meth) acrylamide; monomers having secondary amino groups such as t-butylaminoethyl (meth) acrylate, diacetone (meta ) Acrylamide, N-vinylacetamide, N, N′-methylenebis (meth) acrylamide, N-vinylcaprolactam, N-acryloylmorpholine, N-acryloylpiperidine, N-methacryloylpiperidine, N-acryloylpyrrolidine, pyridyl (meth) acrylate, Examples include pyrrolyl (meth) acrylate and 3- (3-pyridinyl) propyl (meth) acrylate. The nitrogen-containing monomer is preferably a tertiary amino group-containing monomer, and particularly preferably N, N-dimethylaminoethyl (meth) acrylate and / or N, N-dimethylaminopropyl (meth) acrylamide. The nitrogen-containing monomer is preferably used as a copolymerization monomer from the viewpoint of durability.

Examples of other functional group-containing monomers include maleic anhydride, itaconic anhydride and other acid anhydride group-containing monomers; allyl sulfonic acid, 2- (meth) acrylamide-2-methylpropane sulfonic acid, (meth) acrylamide propane sulfone Examples thereof include sulfonic acid group-containing monomers such as acid and sulfopropyl (meth) acrylate; and phosphoric acid group-containing monomers such as 2-hydroxyethylacryloyl phosphate.

Furthermore, as a copolymerizable monomer other than the above, an alkyl (meth) acrylate containing an aromatic ring can be used. Examples of the alkyl (meth) acrylate containing an aromatic ring include phenoxyethyl (meth) acrylate, benzyl (meth) acrylate, phenoxy-2-hydroxypropyl (meth) acrylate, phenol ethylene oxide modified (meth) acrylate, 2 -Naphthoxyethyl (meth) acrylate, 2- (4-methoxy-1-naphthoxy) ethyl (meth) acrylate, phenoxypropyl (meth) acrylate, phenoxyethylene glycol (meth) acrylate, thiophenyl (meth) acrylate, phenyl (meth) acrylate And polystyryl (meth) acrylate.

Furthermore, as copolymerization monomers other than those mentioned above, vinyl monomers such as vinyl acetate, vinyl propionate, N-vinylcarboxylic amides, styrene, α-methylstyrene, N-vinylcaprolactam; acrylonitrile, methacrylonitrile, etc. Nitrile monomers: Epoxy group-containing acrylic monomers such as glycidyl (meth) acrylate; Glycol acrylic ester monomers such as methoxypolypropylene glycol (meth) acrylate; Fluorine (meth) acrylate, Silicone (meth) acrylate, 2-methoxyethyl (Meth) acrylate monomers such as acrylate can also be used.

(Meth) acrylic polymer is mainly composed of alkyl (meth) acrylate in the weight ratio of all constituent monomers. The ratio of the copolymerization monomer in the (meth) acrylic polymer is not particularly limited, but the ratio of the copolymerization monomer is about 0 to 50%, about 0.01 to 15% in the weight ratio of all constituent monomers. Further, it is preferably about 0.1 to 10%.

Among these copolymer monomers, a hydroxyl group-containing monomer and a carboxyl group-containing monomer are preferably used from the viewpoint of adhesion and durability. These copolymerization monomers serve as reaction points with the crosslinking agent when the pressure-sensitive adhesive composition contains a crosslinking agent. Since a hydroxyl group-containing monomer, a carboxyl group-containing monomer, and the like are rich in reactivity with the intermolecular crosslinking agent, they are preferably used for improving the cohesiveness and heat resistance of the resulting pressure-sensitive adhesive layer.

When the copolymerization monomer contains a hydroxyl group-containing monomer and a carboxyl group-containing monomer, these copolymerization monomers are used in the proportion of the copolymerization monomer, but the carboxyl group-containing monomer is 0.1 to 10% by weight and the hydroxyl group-containing monomer. It is preferable to contain 0.01 to 2% by weight. The carboxyl group-containing monomer is more preferably 0.2 to 8% by weight, and further preferably 0.6 to 6% by weight. The hydroxyl group-containing monomer is more preferably 0.03 to 1.5% by weight, and even more preferably 0.05 to 1% by weight.

The (meth) acrylic polymer of the present invention usually has a weight average molecular weight in the range of 1 million to 3 million. In view of durability, particularly heat resistance, it is preferable to use those having a weight average molecular weight of 1.5 million to 2.5 million. Further, it is more preferably 1.7 million to 2.5 million, and further preferably 1.8 million to 2.5 million. When the weight average molecular weight is less than 1,000,000, it is not preferable from the viewpoint of heat resistance. Moreover, when a weight average molecular weight becomes larger than 3 million, it is unpreferable also at the point which bonding property and adhesive force fall. The weight average molecular weight is a value measured by GPC (gel permeation chromatography) and calculated in terms of polystyrene.

<Measurement of weight average molecular weight>
The weight average molecular weight of the obtained (meth) acrylic polymer was measured by GPC (gel permeation chromatography). The sample was prepared by dissolving the sample in dimethylformamide to give a 0.1% by weight solution, which was allowed to stand overnight and then filtered through a 0.45 μm membrane filter.
・ Analyzer: manufactured by Tosoh Corporation, HLC-8120GPC
Column: Super AWM-H, AW4000, AW2500, manufactured by Tosoh Corporation
・ Column size: 6.0mmφ × 150mm each
・ Eluent: 30 mM-lithium bromide, 30 mM-phosphoric acid in dimethylformamide ・ Flow rate: 0.4 ml / min
・ Detector: Differential refractometer (RI)
-Column temperature: 40 ° C
・ Injection volume: 20 μl
The production of such a (meth) acrylic polymer can be appropriately selected from known production methods such as solution polymerization, bulk polymerization, emulsion polymerization, and various radical polymerizations. Further, the (meth) acrylic polymer obtained may be any of a random copolymer, a block copolymer, a graft copolymer, and the like.

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

The polymerization initiator, chain transfer agent, emulsifier and the like used for radical polymerization are not particularly limited and can be appropriately selected and used. In addition, the weight average molecular weight of a (meth) acrylic-type polymer can be controlled by the usage-amount of a polymerization initiator and a chain transfer agent, and reaction conditions, The usage-amount is suitably adjusted according to these kinds.

In the pressure-sensitive adhesive composition for an optical film of the present invention, it is preferable to use a silane coupling agent. As the silane coupling agent, one having an appropriate functional group can be appropriately selected. Examples of the functional group include a vinyl group, an epoxy group, a methacryloxy group, an amino group, a mercapto group, an acryloxy group, an acetoacetyl group, an isocyanate group, a styryl group, and a polysulfide group.

Specific examples of the silane coupling agent include vinyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, p-styryltrimethoxysilane, and γ-methacryloxypropyltrimethoxy. Silane, γ-acryloxypropyltrimethoxysilane, N-β (aminoethyl) γ-aminopropyltrimethoxysilane, γ-aminopropylmethoxysilane, γ-mercaptopropylmethyldimethoxysilane, bis (triethoxysilylpropyl) tetrasulfide , Γ-isocyanatopropyltrimethoxysilane and the like.

The commercially available silane coupling agent can be used as it is. Or a solvent and an additive can also be added and used for a commercially available thing. Examples of commercially available silane coupling agents include KA series (trade name “KA-1003”, etc.) manufactured by Shin-Etsu Silicone Co., Ltd., and KBM series (trade names “KBM-303, KBM-403, KBM-503”, etc.) manufactured by the same company. ”, KBE series (trade names“ KBE-402, KBE-502, KBE-903, etc. ”) manufactured by the same company, SH series (trade names“ SH6020, SH6040, SH6062 etc. ”) manufactured by Toray Industries, Inc., SZ series (product) The names “SZ6030, SZ6032, SZ6300, etc.” are mentioned.

The compounding amount of the silane coupling agent can be appropriately selected according to the purpose. The blending amount (weight ratio) is preferably 0.001 to 2.0, more preferably 0.005 to 2.0, and particularly preferably 0.001 to 2.0 with respect to the acrylic (co) polymer. It is 01 to 1.0, and most preferably 0.02 to 0.5. By making the compounding quantity of the said silane coupling agent into said range, the laminated | multilayer film in which peeling and a bubble do not generate | occur | produce even in the severer high temperature and humid environment can be obtained.

The pressure-sensitive adhesive composition preferably contains a cross-linking agent. Examples of the crosslinking agent include organic crosslinking agents and polyfunctional metal chelates. Examples of the organic crosslinking agent include an epoxy crosslinking agent, an isocyanate crosslinking agent, an imine crosslinking agent, and a peroxide crosslinking agent. These crosslinking agents can be used alone or in combination of two or more. As the organic crosslinking agent, an isocyanate crosslinking agent is preferable. A polyfunctional metal chelate is one in which a polyvalent metal is covalently or coordinately bonded to an organic compound. Examples of polyvalent metal atoms 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. can give. Examples of the atom in the organic compound that is covalently bonded or coordinated 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 blending ratio of the base polymer and the crosslinking agent is not particularly limited, but is usually blended at a ratio of about 10 parts by weight or less of the crosslinking agent (solid content) with respect to 100 parts by weight of the base polymer (solid content). The blending ratio of the crosslinking agent is preferably 0.001 to 10 parts by weight, more preferably 0.01 to 5 parts by weight, and still more preferably 0.2 to 1.0 parts by weight.

Among the crosslinking agents, isocyanate-based crosslinking agents are preferable. Examples of the isocyanate-based crosslinking agent include aromatic isocyanates such as tolylene diisocyanate and xylene diisocyanate, alicyclic isocyanates such as isophorone diisocyanate, and aliphatic isocyanates such as hexamethylene diisocyanate.

More specifically, for example, lower aliphatic polyisocyanates such as butylene diisocyanate and hexamethylene diisocyanate, alicyclic isocyanates such as cyclopentylene diisocyanate, cyclohexylene diisocyanate and isophorone diisocyanate, 2,4-tolylene diisocyanate, Aromatic diisocyanates such as 4,4'-diphenylmethane diisocyanate, xylylene diisocyanate, polymethylene polyphenyl isocyanate, trimethylolpropane / tolylene diisocyanate trimer adduct (trade name Coronate L, manufactured by Nippon Polyurethane Industry Co., Ltd.), tri Methylolpropane / hexamethylene diisocyanate trimer adduct (trade name Coronate HL, manufactured by Nippon Polyurethane Industry Co., Ltd.), hexamethylene dii Isocyanurate of cyanate (product name: Coronate HX, manufactured by Nippon Polyurethane Industry Co., Ltd.), polyether polyisocyanate, polyester polyisocyanate, and adducts of these with various polyols, isocyanurate bond, burette bond And polyisocyanates polyfunctionalized with allophanate bonds.

Furthermore, the pressure-sensitive adhesive composition of the present invention may contain other known additives as necessary, for example, powders such as colorants and pigments, dyes, surfactants, plasticizers, Tackifier, surface lubricant, leveling agent, softener, antioxidant, anti-aging agent, light stabilizer, UV absorber, polymerization inhibitor, inorganic or organic filler, metal powder, particulate, foil It can be added as appropriate depending on the purpose of using the product. Moreover, you may employ | adopt the redox system which added a reducing agent within the controllable range.

The optical film pressure-sensitive adhesive layer can be formed by applying a heat treatment to a substrate and then curing it. In the pressure-sensitive adhesive optical film of the present invention, a pressure-sensitive adhesive layer is formed on at least one surface of the optical film with the pressure-sensitive adhesive.

As a method for forming the pressure-sensitive adhesive layer, for example, using a separator or the like that has been peeled off as a base material, the pressure-sensitive adhesive composition is applied to the separator, the polymerization solvent or the like is removed by drying, and the pressure-sensitive adhesive is cured. There is a method of transferring to an optical film after forming the layer. Further, as a method of forming the pressure-sensitive adhesive layer, for example, using an optical film as a substrate, the pressure-sensitive adhesive composition is directly applied to the optical film, and the polymerization solvent and the like are removed by drying and cured to be a pressure-sensitive adhesive. A method for forming a layer on an optical film is mentioned. In applying the pressure-sensitive adhesive, one or more solvents other than the polymerization solvent may be added as appropriate.

In preparing the pressure-sensitive adhesive optical film of the present invention, an anchor layer may be formed on the surface of the optical film, or a pressure-sensitive adhesive layer may be formed after various easy adhesion treatments such as corona treatment and plasma treatment. it can. Moreover, you may perform an easily bonding process on the surface of an adhesive layer.

As the material for forming the anchor layer, an anchor agent selected from polyurethane, polyester, and polymers containing an amino group in the molecule is preferably used, and polymers containing an amino group in the molecule are particularly preferred. . Polymers containing an amino group in the molecule ensure good adhesion because the amino group in the molecule exhibits an interaction such as a reaction or ionic interaction with the carboxyl group in the pressure-sensitive adhesive.

Examples of the polymer containing an amino group in the molecule include polymers of amino-containing group-containing monomers such as polyethyleneimine, polyallylamine, polyvinylamine, polyvinylpyridine, polyvinylpyrrolidine, and dimethylaminoethyl acrylate.

Various methods are used as a method for forming the pressure-sensitive adhesive layer. Specifically, for example, roll coat, kiss roll coat, gravure coat, reverse coat, roll brush, spray coat, dip roll coat, bar coat, knife coat, air knife coat, curtain coat, lip coat, die coater, etc. Examples thereof include an extrusion coating method.

The thickness of the pressure-sensitive adhesive layer is preferably 5 to 50 μm, more preferably 10 to 25 μm, for the purpose of maintaining the durability of the heat test and the wet heat test while ensuring a sufficient adhesive force.

In the present invention, the adhesive layer is protected with a releasable carrier film (also referred to as a separator) until it is bonded to the liquid crystal cell.

Examples of the constituent material of the separator include porous materials such as plastic film, paper, cloth, and non-woven fabric, nets, foam sheets, metal foils, and laminates thereof, but have excellent surface smoothness. From the above, a plastic film is preferably used.

Examples of the plastic film include polyethylene film, polypropylene film, polybutene film, polybutadiene film, polymethylpentene film, polyvinyl chloride film, vinyl chloride copolymer film, polyethylene terephthalate film, polybutylene terephthalate film, polyurethane film, and ethylene. -Vinyl acetate copolymer film. Of these, polyester films such as polyethylene terephthalate film, polybutylene terephthalate film, and polyethylene naphthalate film are preferable.

For the separator, if necessary, mold release and antifouling treatment with a silicone type, fluorine type, long chain alkyl type or fatty acid amide type release agent, silica powder, etc., coating type, kneading type, vapor deposition type It is also possible to carry out antistatic treatment such as. In particular, the release property from the pressure-sensitive adhesive layer can be further improved by appropriately performing a release treatment such as silicone treatment, long-chain alkyl treatment, or fluorine treatment on the surface of the separator. The pressure-sensitive adhesive layer of the present invention is suitable for a separator that has been subjected to a release treatment, and is particularly suitable for a separator that has been subjected to a release treatment by a silicone treatment.

In addition, the sheet | seat which carried out the peeling process used in preparation of said adhesive optical film can be used as a separator of an adhesive optical film as it is, and can simplify in a process surface.

As the optical film, one used for forming an image display device such as a liquid crystal display device is used, and the type thereof is not particularly limited. For example, the optical film includes a polarizing plate. A polarizing plate having a transparent protective film on one or both sides of a polarizer is generally used.

The polarizer is not particularly limited, and various types can be used. Examples of polarizers include dichroic iodine and dichroic dyes on hydrophilic polymer films such as polyvinyl alcohol films, partially formalized polyvinyl alcohol films, and ethylene / vinyl acetate copolymer partially saponified films. Examples thereof include polyene-based oriented films such as those obtained by adsorbing substances and uniaxially stretched, polyvinyl alcohol dehydrated products and polyvinyl chloride dehydrochlorinated products. Among these, a polarizer composed of a polyvinyl alcohol film and a dichroic material such as iodine is preferable. The thickness of these polarizers is not particularly limited, but is generally about 5 to 80 μm.

A polarizer in which a polyvinyl alcohol film is dyed with iodine and uniaxially stretched can be prepared, for example, by dyeing polyvinyl alcohol in an aqueous solution of iodine and stretching it 3 to 7 times the original length. If necessary, it can be immersed in an aqueous solution such as potassium iodide which may contain boric acid, zinc sulfate, zinc chloride or the like. Further, if necessary, the polyvinyl alcohol film may be immersed in water and washed before dyeing. In addition to washing the polyvinyl alcohol film surface with dirt and anti-blocking agents by washing the polyvinyl alcohol film with water, it also has the effect of preventing unevenness such as uneven coloring by swelling the polyvinyl alcohol film. is there. Stretching may be performed after dyeing with iodine, may be performed while dyeing, or may be dyed with iodine after stretching. The film can be stretched even in an aqueous solution such as boric acid or potassium iodide or in a water bath.

As a material constituting the transparent protective film, for example, a thermoplastic resin excellent in transparency, mechanical strength, thermal stability, moisture barrier property, isotropy and the like is used. Specific examples of such thermoplastic resins include cellulose resins such as triacetyl cellulose, polyester resins, polyethersulfone resins, polysulfone resins, polycarbonate resins, polyamide resins, polyimide resins, polyolefin resins, (meth) acrylic resins, cyclic Examples thereof include polyolefin resins (norbornene resins), polyarylate resins, polystyrene resins, polyvinyl alcohol resins, and mixtures thereof. A transparent protective film is bonded to one side of the polarizer by an adhesive layer. On the other side, as a transparent protective film, (meth) acrylic, urethane-based, acrylurethane-based, epoxy-based, silicone A thermosetting resin such as a system or an ultraviolet curable resin can be used. One or more kinds of arbitrary appropriate additives may be contained in the transparent protective film. Examples of the additive include an ultraviolet absorber, an antioxidant, a lubricant, a plasticizer, a release agent, a coloring inhibitor, a flame retardant, a nucleating agent, an antistatic agent, a pigment, and a coloring agent. The content of the thermoplastic resin in the transparent protective film is preferably 50 to 100% by weight, more preferably 50 to 99% by weight, still more preferably 60 to 98% by weight, and particularly preferably 70 to 97% by weight. . When content of the said thermoplastic resin in a transparent protective film is 50 weight% or less, there exists a possibility that the high transparency etc. which a thermoplastic resin originally has cannot fully be expressed.

In addition, as an optical film, for example, it is used for forming a liquid crystal display device such as a reflection plate, an anti-transmission plate, a retardation plate (including wavelength plates such as 1/2 and 1/4), a visual compensation film, and a brightness enhancement film. And an optical layer that may be formed. These can be used alone as an optical film, or can be laminated on the polarizing plate for practical use and used as one layer or two or more layers.

An optical film in which the optical layer is laminated on a polarizing plate can be formed by a method of sequentially laminating separately in the manufacturing process of a liquid crystal display device or the like. There is an advantage that the manufacturing process of a liquid crystal display device or the like can be improved because of excellent stability and assembly work. For the lamination, an appropriate adhesive means such as an adhesive layer can be used. When adhering the polarizing plate and the other optical layer, their optical axes can be set at an appropriate arrangement angle in accordance with the target phase difference characteristic.

The wound body of the optical sheet member of the present invention is a liquid crystal cell in which an optical sheet member having a releasable carrier film is drawn out through an adhesive layer on at least one surface of the optical film and half-cut at a predetermined interval It is preferably used for the purpose of pasting together. Here, the half cut is a cutting method in which the optical film and the pressure-sensitive adhesive layer are cut while leaving the releasable carrier film. At that time, the pressure-sensitive adhesive layer is preferably completely cut, but may partially remain. Such a manufacturing process can be suitably implemented by the continuous manufacturing method of the liquid crystal display device of the present invention.

That is, the continuous manufacturing method of the liquid crystal display device of the present invention includes a step of unwinding the optical sheet member from the wound body of the optical sheet member of the present invention, and the releasable carrier film at a predetermined interval between the unrolled optical sheet member. A step of cutting the optical film and the pressure-sensitive adhesive layer while leaving a film, and a step of bonding the cut optical film piece to the liquid crystal cell via the pressure-sensitive adhesive layer. FIG. 1 is a process diagram showing an example of a continuous manufacturing method of a liquid crystal display device of the present invention. Hereinafter, each process is demonstrated based on this.

(1) First roll original fabric preparation step (FIG. 1, S1). The wound body of the present invention is prepared as a first roll raw fabric. The width | variety of a 1st roll original fabric is dependent on the bonding size of an optical display unit.

(2) Transfer process (FIG. 1, S2). The first optical sheet member is fed out from the first roll prepared and installed, and is conveyed downstream. The first transport device that transports the first optical sheet member includes, for example, a nip roller pair, a tension roller, a rotation drive device, an accumulation device, a sensor device, and a control device. The first optical sheet member has a first release film, which functions as a carrier film.

(3) First inspection process (FIG. 1, S3). A defect of the first optical sheet member is inspected using a first defect inspection apparatus. The defect inspection method here is a method of photographing and processing images with transmitted light and reflected light on both sides of the first optical sheet member, and an inspection polarizing film between the CCD camera and the inspection object. A method of taking an image and processing an image by arranging it so as to be crossed Nicols with the polarization axis of the target polarizing plate (sometimes referred to as 0 degree cross), and a polarizing film for inspection between the CCD camera and the inspection object In addition, it is arranged (sometimes referred to as x degree cross) so as to be at a predetermined angle (for example, a range of greater than 0 degree and within 10 degrees) with the polarization axis of the polarizing plate to be inspected, and image photographing / image processing is performed. A method is mentioned. Note that a known method can be applied to the image processing algorithm, and for example, a defect can be detected by density determination by binarization processing.

In the image capturing / image processing method using transmitted light, foreign matter inside the first optical sheet member can be detected. In the image capturing / image processing method using the reflected light, the adhered foreign matter on the surface of the first optical sheet member can be detected. In the image photographing / image processing method using the 0-degree cross, mainly surface foreign matter, dirt, internal foreign matter, etc. can be detected as bright spots. In the image photographing / image processing method using the x-degree cross, a nick can be mainly detected.

The defect information obtained by the first defect inspection apparatus is linked with the position information (for example, position coordinates), transmitted to the control apparatus, and can contribute to the cutting method by the first cutting apparatus described later. .

(4) First cutting step (FIG. 1, S4). The first cutting device cuts (half-cuts) the first optical film and the first pressure-sensitive adhesive layer into a predetermined size without cutting the first release film. Examples of the cutting means include a laser device, a cutter, and other known cutting means. Based on the defect information obtained by the first defect inspection apparatus, the apparatus is configured to cut so as to avoid the defect. Thereby, the yield of the first optical sheet member is greatly improved. The first optical sheet member including the defect is excluded by a first exclusion device described later, and is configured not to be attached to the optical display unit.

(5) 1st optical film bonding process (FIG. 1, S5). While removing the first release film using the first peeling device, the first optical film from which the first release film has been removed using the first laminating device is optically displayed through the first adhesive layer. Affix to unit. At the time of bonding, as will be described later, the first optical film and the optical display unit are sandwiched between a pair of rolls and are bonded.

(6) Cleaning step (FIG. 1, S6). The surface of the optical display unit is cleaned by a polishing cleaning device and a water cleaning device. The cleaned panel is transported to the inspection apparatus by the transport mechanism. The transport mechanism includes, for example, a transport roller, a transport direction switching mechanism, a rotation drive device, a sensor device, and a control device.

(7) Second roll original fabric preparation step (FIG. 1, S11). The wound body of this invention is prepared as a 2nd roll original fabric. The laminated structure of the second optical sheet member has the same configuration as that of the first optical sheet member, but is not limited thereto.

(8) Transfer process (FIG. 1, S12). The second optical sheet member is unwound from the prepared and installed second roll, and conveyed downstream. The second transport device that transports the second optical sheet member includes, for example, a nip roller pair, a tension roller, a rotation drive device, an accumulation device, a sensor device, and a control device.

(9) Second inspection step (FIG. 1, S13). A defect of the second optical sheet member is inspected using a second defect inspection apparatus. The defect inspection method here is the same as the method using the first defect inspection apparatus described above.

(10) Second cutting step (FIG. 1, S14). The second cutting device cuts (half-cuts) the second optical film and the second pressure-sensitive adhesive layer to a predetermined size without cutting the second release film. Examples of the cutting means include a laser device, a cutter, and other known cutting means. Based on the defect information obtained by the second defect inspection apparatus, the apparatus is configured to cut so as to avoid the defect. Thereby, the yield of the second optical sheet member is significantly improved. The second optical sheet member including the defect is excluded by a second exclusion device described later, and is configured not to be attached to the optical display unit.

(11) Second optical film bonding step (FIG. 1, S15). Then, after the second cutting step, while removing the second release film using the second peeling device, the second optical film from which the second release film has been removed using the second bonding device, A second adhesive layer is bonded to a surface different from the surface to which the first optical film of the optical display unit is bonded. In addition, before bonding a 2nd optical film to an optical display unit, when an optical display unit is rotated 90 degree | times by the conveyance direction switching mechanism of a conveyance mechanism, a 1st optical film and a 2nd optical film are made into the relationship of a cross Nicole. There is. At the time of pasting, as will be described later, the second optical film and the optical display unit are sandwiched between rolls and pressure bonded.

(12) Optical display unit inspection process (FIG. 1, S16). The inspection device inspects an optical display unit having optical films attached to both sides. Examples of the inspection method include a method of taking an image and processing an image using reflected light on both sides of the optical display unit. As another method, a method of installing a polarizing film for inspection between the CCD camera and the inspection object is also exemplified. Note that a known method can be applied to the image processing algorithm, and for example, a defect can be detected by density determination by binarization processing.

(13) A non-defective product of the optical display unit is determined based on the defect information obtained by the inspection apparatus. The optical display unit determined to be non-defective is transported to the next mounting process. If a defective product is determined, a rework process is performed, a new optical film is applied, and then inspected.If a good product is determined, the process proceeds to a mounting process. Discarded.

In the series of manufacturing processes described above, the optical display unit can be suitably manufactured by executing the first optical film bonding process and the second optical film bonding process on a continuous production line.

The formation of the liquid crystal display device of the present invention can be carried out according to the conventional method. That is, a liquid crystal display device is generally formed by appropriately assembling components such as a liquid crystal cell, an optical film, and an illumination system as necessary, and incorporating a drive circuit. As the liquid crystal cell, for example, an arbitrary type such as a TN type, STN type, π type, VA type, or IPS type can be used.

Appropriate liquid crystal display devices such as a liquid crystal display device in which an adhesive optical film is disposed on one side or both sides of a liquid crystal cell, and a backlight or reflector used in an illumination system can be formed. In that case, the optical film according to the present invention can be installed on one side or both sides of the liquid crystal cell. When optical films are provided on both sides, they may be the same or different.

Further, when forming a liquid crystal display device, for example, a single layer or a suitable part such as a diffusing plate, an antiglare layer, an antireflection film, a protective plate, a prism array, a lens array sheet, a light diffusing plate, a backlight, etc. Two or more layers can be arranged.

Hereinafter, the present invention will be specifically described by way of examples, but the present invention is not limited to these examples. In addition, all the parts and% in each example are based on weight. Evaluation items in Examples and the like were measured as follows.

(Storage)
The produced polarizing plate roll with a carrier film adhesive layer was stored for 3 months. Then, 100 sheets were bonded together in the process shown in FIG. 1 to obtain a liquid crystal display device. Appearance inspection (parts other than the cut end face) of the obtained liquid crystal display device was performed and evaluated according to the following evaluation criteria. In the single wafer system of Reference Examples 2 and 3, 20 sheets of punched sheet products were stacked and packed, and similarly stored for 3 months. ○ indicates that 0 out of 100 sheets are defective in appearance, Δ indicates that 1 to 5 out of 100 sheets are defective in appearance, and x indicates that 6 or more out of 100 sheets are defective in appearance.

(Adhesive state of cut surface)
As described above, the appearance of the liquid crystal display device obtained by laminating 100 sheets in the step shown in FIG. 1 (the state of adhesive adhesion on the cut end face) was evaluated and evaluated according to the following evaluation criteria. ○ is 0 to less than 3 out of 100 sheets with poor appearance, and x is 3 or more out of 100 with poor appearance. In addition, the conditions of the half cut were cut at a speed of 20 m / min using a cutter blade as a cutting blade.

(Moist heat test)
The pressure-sensitive adhesive layer-attached polarizing plate was attached to a glass plate (non-alkali glass) and heated in an atmosphere of 60 ° C. and 90% RH for 500 hours, and then the presence or absence of peeling was visually observed.

Example 1
Four-necked flask equipped with 95 parts of butyl acrylate (BA), 5 parts of acrylic acid (AA), 0.1 part of 2,2-azobisisobutyronitrile, 140 parts of ethyl acetate, and a nitrogen introduction tube and a cooling tube The polymer was sufficiently purged with nitrogen and then subjected to a polymerization reaction at 55 ° C. for 8 hours while stirring under a nitrogen stream to obtain a high molecular weight polymer A having a weight average molecular weight of 1.7 million.

To 100 parts of the solid content of this polymer solution, 0.5 part of a polyisocyanate-based cross-linking agent (product name Coronate L: manufactured by Nippon Polyurethane) composed of a tolylene diisocyanate adduct of trimethylolpropane, 3-glycidoxypropyltri Methoxysilane (product name KBM403: manufactured by Shin-Etsu Silicone) was blended. Next, the pressure-sensitive adhesive composition was dried and applied to a PET carrier film (product name: MRF38: manufactured by Mitsubishi Plastics) having a thickness of 38 μm, which was subjected to silicone release treatment so that the thickness became 25 μm, using a fountain coater. And dried for 2 minutes to obtain an adhesive layer. The pressure-sensitive adhesive layer was bonded to a polarizing plate roll and transferred to obtain a polarizing plate roll with a carrier film / pressure-sensitive adhesive layer. Table 1 shows the physical properties and evaluation results of each layer.

In addition, the polarizing plate was produced as follows. A 80 μm-thick polyvinyl alcohol film was stretched up to 3 times while being dyed for 1 minute in an iodine solution of 0.3% concentration at 30 ° C. between rolls having different speed ratios. Thereafter, the total draw ratio was stretched to 6 times while being immersed in an aqueous solution containing 60% at 4% concentration of boric acid and 10% concentration of potassium iodide for 0.5 minutes. Next, after washing by immersing in an aqueous solution containing potassium iodide at 30 ° C. and 1.5% concentration for 10 seconds, drying was performed at 50 ° C. for 4 minutes to obtain a polarizer. A saponified 80 μm thick triacetyl cellulose film was bonded to both surfaces of the polarizer with a polyvinyl alcohol-based adhesive to prepare a polarizing plate.
<Plateing the polarizing plate to the liquid crystal cell>
According to the process shown in FIG. 1, the optical film was bonded to a liquid crystal cell using the polarizing film roll with a carrier film and an adhesive layer. The liquid crystal cell corresponds to a 32-inch television having a glass substrate, and the size of the optical film was 400 mm × 700 mm.

Example 2
In Example 1, except that the addition amount of the polyisocyanate-based crosslinking agent was changed to 0.3 part, a polarizing plate roll with a carrier film / adhesive layer was obtained under the same conditions as in Example 1, and then a liquid crystal panel The pasting was done. Table 1 shows the physical properties and evaluation results of each layer.

Example 3
In Example 1, except that the polymer A was replaced with the polymer B, a polarizing plate roll with a carrier film / adhesive layer was obtained under the same conditions as in Example 1, and then bonded to the liquid crystal panel. Table 1 shows the physical properties and evaluation results of each layer. Polymer B was polymerized as follows.

99 parts of butyl acrylate (BA), 1 part of 4-hydroxybutyl acrylate (HBA), 0.1 part of 2,2-azobisisobutyronitrile, 140 parts of ethyl acetate, 4 equipped with a nitrogen introduction tube and a cooling tube After putting into a one-necked flask and sufficiently purging with nitrogen, a polymerization reaction was carried out at 55 ° C. for 8 hours while stirring under a nitrogen stream to obtain a high molecular weight polymer B having a weight average molecular weight of 1.7 million.

Comparative Examples 1 and 2
In Example 1, after obtaining the polarizing plate roll with a carrier film and an adhesive layer on the same conditions as Example 1 except having changed the addition amount of the polyisocyanate type crosslinking agent into the amount shown in Table 1, liquid crystal Bonding to the panel was performed. Table 1 shows the physical properties and evaluation results of each layer.

Comparative Example 3
In Example 1, while changing the polymer A to the polymer B and changing the addition amount of the polyisocyanate-based crosslinking agent to 0.1 part, the polarized light with a carrier film / adhesive layer was the same as in Example 1. After obtaining the plate roll, it was bonded to the liquid crystal panel. Table 1 shows the physical properties and evaluation results of each layer.

Comparative Example 4
In Example 1, except that the polymer A was replaced with the polymer C, a polarizing plate roll with a carrier film / adhesive layer was obtained under the same conditions as in Example 1, and then bonded to the liquid crystal panel. Table 1 shows the physical properties and evaluation results of each layer. Polymer C was polymerized as follows.

Four-necked flask equipped with 93 parts of butyl acrylate (BA), 7 parts of acrylic acid (AA), 0.1 part of 2,2-azobisisobutyronitrile, 140 parts of ethyl acetate, and a nitrogen introduction tube and a cooling tube The polymer was sufficiently purged with nitrogen and then subjected to a polymerization reaction at 55 ° C. for 8 hours with stirring under a nitrogen stream to obtain a high molecular weight polymer C having a weight average molecular weight of 1.7 million.

Comparative Example 5
In Example 1, with the same conditions as in Example 1 except that the polymer A was replaced with the polymer B and the addition amount of the crosslinking agent was changed to 1.5 parts (see Table 1). After obtaining a polarizing plate roll, it bonded to the liquid crystal panel. Table 1 shows the physical properties and evaluation results of each layer.

Comparative Example 6
In Example 1, a polarizing plate roll with a carrier film / adhesive layer was obtained under the same conditions as in Example 1 except that the addition amount of the polyisocyanate-based crosslinking agent was changed to 2.0 parts (see Table 1). Then, bonding to the liquid crystal panel was performed. Table 1 shows the physical properties and evaluation results of each layer.

Claims

A wound body of an optical sheet member,
The optical sheet member has a releasable carrier film via an adhesive layer on at least one side of the optical film,
The pressure-sensitive adhesive layer is made of an acrylic (co) polymer,
The storage elastic modulus is 0.9 to 1.2 MPa when a shear strain (thickness 800 μm, dynamic strain 0.1%) is applied at 23 ° C. and a frequency of 10 Hz,
The elongation at break in the tensile test is 500-2000%,
Adhesive strength when peeled off at 180 ° at a peeling speed of 300 mm / min 1 minute after application to the surface of smooth stainless steel (SUS304: Guangei Industry Co., Ltd.) by reciprocating once using a 2 kg roller is 3 to A wound body of an optical sheet member that is 15 N / 25 mm.
The pressure-sensitive adhesive layer has a gel fraction of 70 to 90%,
The wound body of the optical sheet member according to claim 1, wherein the holding power ( HA ) at 23 ° C. measured by the following evaluation method is 200 μm or less.
Here, the holding force (H A ) is a 10 mm × 30 mm optical film with an upper end of 10 mm × 10 mm attached to an alkali-free glass plate (Corning 1737, thickness 0.7 mm) with a pressing force of 2 Kg through an adhesive layer. And then autoclaved for 15 minutes at 50 ° C. and 5 atmospheres, left at room temperature for 1 hour, and then loaded with a load of 500 g on the lower end of the optical film and left for 1 hour. It represents the width of deviation from the front and rear glass plates.
The wound body of an optical sheet member according to claim 1, wherein the releasable carrier film is made of a polyester base material.
The step of unwinding the optical sheet member from the wound body of the optical sheet member according to any one of claims 1 to 3, and the optical sheet member while leaving the releasable carrier film at a predetermined interval. A continuous manufacturing method of a liquid crystal display comprising: a step of cutting a film and the pressure-sensitive adhesive layer; and a step of bonding the cut optical film piece to a liquid crystal cell via the pressure-sensitive adhesive layer.