KR20070101774A - Process for producing a polarizing plate and a polarizing plate with an adhesive - Google Patents

Abstract

A method for producing a polarizing plate and a polarizing plate with an adhesive are provided to prevent process contamination caused by powder materials by performing a corona discharge treatment on the surface of a cycloolefin-based resin film with the output intensity below a predetermined value. In a method for producing a polarizing plate by adhering a cycloolefin-based resin film on at least one side of a polarizing film including polyvinyl alcohol-based resin, a corona discharge treatment is performed with the output intensity below 800W on the surface of the cycloolefin-based resin film, which is adhered to the polarizing film, and then an adhesive is coated on the corona discharge treated surface to adhere the polarizing film. The cycloolefin-based resin film has the thickness of 20 to 100mum.

Description

Process for Producing a Polarizing Plate and a Polarizing Plate with an Adhesive

1 is a graph showing the results of Examples 1 and 2 by taking the corona output intensity on the horizontal axis and the corona integrated irradiation dose on the vertical axis, ○ indicates that the fine powder material is not recognized, × indicates that the fine powder substance is generated Graph showing what happened.

1. Japanese Patent Publication No. 2005-213314

2. Japanese Patent Publication No. 2001-350018

3. Japanese Patent Publication No. 2000-241627

4. Japanese Patent Publication No. 8-43812

5. Japanese Patent Publication No. 2005-70140

6. Japanese Patent Publication No. 2005-181817

7. Japanese Patent Publication No. 2005-208456

MEANS TO SOLVE THE PROBLEM This invention is a method of manufacturing a polarizing plate by laminating | stacking a cycloolefin resin film through the adhesive agent on at least one surface of the polarizing film containing polyvinyl alcohol-type resin, and the cycloolefin resin film side of the polarizing plate obtained by the method. It is related with the method of manufacturing a polarizing plate with an adhesive by providing an adhesive layer in the adhesive. Specifically, it is intended to produce a polarizing plate having a good appearance with such a configuration with less process contamination.

The polarizing plate is usually laminated with a transparent resin film, for example, a cellulose acetate-based film represented by triacetyl cellulose through an adhesive layer on one or both sides of a polarizing film containing a polyvinyl alcohol-based resin in which a dichroic dye is adsorbed and oriented. It is in one configuration. This is bonded together with an adhesive to a liquid crystal cell through other optical films, such as an optical compensation film and retardation film, as needed, and it becomes a component of a liquid crystal display device.

An adhesive is generally provided in the surface by which it is bonded to liquid crystal cells, such as a polarizing plate, it is protected by another film, the other film is peeled off immediately before bonding, and it is bonded by the liquid crystal cell on the adhesive surface. Then, in order to increase the adhesive force between the polarizing plate and the pressure-sensitive adhesive layer and to release the pressure-sensitive adhesive on the liquid crystal cell glass even when a problem occurs in bonding to the liquid crystal cell (so-called reworkability), Japanese Patent Laid-Open No. 7- 174918 discloses a surface active treatment such as corona treatment, plasma treatment, ultraviolet irradiation, electron beam irradiation, anchoring agent coating, and the like on the surface of the pressure-sensitive adhesive layer previously formed on a separate film, A method of joining is disclosed. In addition, Japanese Unexamined Patent Application Publication No. 2005-213314 discloses a surface activation treatment such as corona discharge treatment on the surfaces to be bonded to a resin film such as a polarizing plate and an adhesive layer, respectively, and by bonding the surfaces on which these treatments have been performed, A method of increasing the adhesion between the two is disclosed.

By the way, the liquid crystal display device is expanding rapidly as a thin display screen, such as a television, various monitors, and a personal computer. In the polarizing plate for liquid crystal television, the optical compensation film is laminated | stacked normally through an adhesive on one side. As the optical compensation film laminated on the polarizing plate, a stretched processed product of a polycarbonate resin film, a stretched processed product of a cycloolefin resin film, and the like are used. The retardation film which consists of a cycloolefin resin film made into a main monomer is used a lot.

Corona discharge treatment is given to the surface of a cycloolefin resin film, and an adhesive layer is provided on it, for example, Such a structure is disclosed by Unexamined-Japanese-Patent No. 2001-350018. Moreover, it is also known to make a cycloolefin resin film as a polarizing plate protective film, and to adhere to the polarizing film via an adhesive agent after performing a corona discharge treatment on the surface, for example, to Unexamined-Japanese-Patent No. 2000-241627. Such a configuration is disclosed.

On the other hand, the polarizing plate of the structure which bonded the retardation film which consists of a cycloolefin resin film directly to the polarizing film for the purpose of reducing the number of components to be comprised, or simplifies a manufacturing process, for the improvement of productivity and a reduction of product cost is also known. . For example, Japanese Patent Laid-Open No. Hei 8-43812 discloses a lamination structure of a cycloolefin resin film / polarizing film / triacetylcellulose film having a function as a retardation film.

In JP-A-2005-70140, JP-A-2005-181817 and JP-A-2005-208456, joining a polyvinyl alcohol polarizing film and a cycloolefin resin film with an aqueous adhesive In these publications, an example in which a cycloolefin-based resin film is subjected to a corona discharge treatment and then bonded to a polarizing film is disclosed.

Thus, when providing an adhesive layer in a cycloolefin resin film, or bonding a cycloolefin resin film to a polarizing film, corona discharge treatment is often performed for the purpose of the adhesive improvement of a cycloolefin resin film.

However, when the corona discharge treatment is applied to the surface of the cycloolefin resin film, a fine powdery substance derived from the cycloolefin resin is generated, and the fine powdery substance accumulates during the long period of continuous corona discharge treatment at the factory level, and the process is performed. It became clear that a problem was contaminated and the appearance of the polarizing plate to which the polarizing plate or the adhesive was attached was damaged.

Therefore, an object of the present invention is to produce a polarizing plate by bonding a cycloolefin resin film to at least one side of a polarizing film containing polyvinyl alcohol-based resin, even when a corona discharge treatment is applied to the surface of the cycloolefin resin film. It is providing the method which can suppress the in-process contamination by the generation | occurrence | production of a fine powder substance, and the appearance defect of a polarizing plate. Another object of the present invention is to form a pressure-sensitive adhesive layer on the polarizing plate obtained as described above, and to form a polarizing plate with a pressure-sensitive adhesive, even when the surface of the cycloolefin-based resin film of the polarizing plate is subjected to corona discharge treatment. The present invention provides a method capable of suppressing in-process contamination and appearance defects of a polarizing plate due to the occurrence of s.

In general, a large amount of integrated irradiation is used as an index indicating the intensity of corona discharge. However, as a result of earnestly researching the inventors based on the above object, the present inventors have found that the generation of fine powdery substance derived from cycloolefin resin is not an integrated irradiation amount. It has been found that it depends greatly on the output at the time of discharge treatment. By controlling the output of the corona discharge treatment within a certain range, it has been found that fine powdery substances do not occur, and thus the present invention has been completed.

That is, according to the present invention, in bonding a cycloolefin resin film to at least one side of a polarizing film containing polyvinyl alcohol-based resin to produce a polarizing plate, the side bonded to the polarizing film of the cycloolefin-based resin film Corona discharge treatment is given to a surface with an output strength of 800 W or less, and then the method of bonding the said polarizing film through an adhesive agent on the process surface is provided.

Moreover, a corona discharge process is performed to the cycloolefin resin film surface of the polarizing plate obtained by said method by the output strength of 800 W or less, and then, a pressure-sensitive adhesive layer is formed on the treated surface to produce a polarizing plate with pressure-sensitive adhesive. A method is also provided.

Best Mode for Carrying Out the Invention

Hereinafter, the present invention will be described in detail. In this invention, the polarizing plate is manufactured by laminating | stacking the cycloolefin resin film by which corona discharge treatment was given to at least one surface of the polarizing film containing polyvinyl alcohol-type resin through an adhesive agent. Moreover, a corona discharge treatment is given to the cycloolefin resin film surface of the polarizing plate obtained in this way, an adhesive layer is provided here and the polarizing plate with an adhesive is manufactured.

Polyvinyl alcohol-type resin which comprises a polarizing film is obtained by saponifying a polyvinyl acetate type resin. As polyvinyl acetate type resin, the copolymer etc. of vinyl acetate and the other monomer copolymerizable with it besides the polyvinyl acetate which is a homopolymer of vinyl acetate are illustrated. As another monomer copolymerized with vinyl acetate, unsaturated carboxylic acids, unsaturated sulfonic acids, olefins, vinyl ethers, acrylamide which has an ammonium group, etc. are mentioned, for example. The saponification degree of polyvinyl alcohol-type resin is about 85-100 mol% normally, Preferably it is 98 mol% or more. The polyvinyl alcohol-based resin may be further modified. For example, polyvinyl formal, polyvinyl acetal, or the like modified with aldehydes can also be used. In addition, the degree of polymerization of the polyvinyl alcohol-based resin is usually about 1,000 to 10,000, preferably about 1,500 to 5,000.

What formed such a polyvinyl alcohol-type resin into a film is used as a raw film of a polarizing film. The method for forming a polyvinyl alcohol-based resin is not particularly limited and can be formed by a known method. Although the film thickness of a polyvinyl alcohol-type raw film is not specifically limited, For example, it is about 10 micrometers-150 micrometers.

The polarizing film is usually a step of uniaxially stretching such a polyvinyl alcohol-based resin film, a step of dyeing the polyvinyl alcohol-based resin film with a dichroic dye to adsorb the dichroic dye, and a polyvinyl alcohol-based adsorbed dichroic dye. It manufactures through the process of processing a resin film with aqueous boric acid solution, and the process of washing with water after the process by this boric acid aqueous solution.

Uniaxial stretching may be performed before dyeing, simultaneous dyeing, or dyeing. When uniaxial stretching is performed after dyeing, this uniaxial stretching may be performed before boric acid treatment or during boric acid treatment. Of course, uniaxial stretching may be performed in these several steps. In uniaxial stretching, you may extend | stretch to 1 axis between rolls from which a circumferential speed differs, or you may extend | stretch to 1 axis using a thermal roll. Moreover, it may be dry stretching, such as extending | stretching in air | atmosphere, or it may be wet extending | stretching extending | stretching in the state swollen with a solvent. The draw ratio is usually about 2 to 8 times.

In order to dye a polyvinyl alcohol-type resin film with a dichroic dye, what is necessary is just to immerse a polyvinyl alcohol-type resin film in the aqueous solution containing a dichroic dye, for example. As a dichroic dye, an iodine or a dichroic dye is used specifically. In addition, the polyvinyl alcohol-based resin film is preferably subjected to an immersion treatment in water before the dyeing treatment.

When using iodine as a dichroic dye, the method of immersing and dyeing a polyvinyl alcohol-type resin film in the aqueous solution containing iodine and potassium iodide is employ | adopted normally. The content of iodine in this aqueous solution is usually about 0.01 to 1 part by weight per 100 parts by weight of water, and the content of potassium iodide is usually about 0.5 to 20 parts by weight per 100 parts by weight of water. The temperature of the aqueous solution used for dyeing is about 20-40 degreeC normally, and the immersion time (dyeing time) in this aqueous solution is about 20-1,800 second normally.

On the other hand, when using a dichroic dye as a dichroic dye, the method of immersing and dyeing a polyvinyl alcohol-type resin film in the aqueous solution containing water-soluble dichroic dye is employ | adopted normally. The content of the dichroic dye in this aqueous solution is usually about 1 × 10 ^-4 to 10 parts by weight, preferably about 1 × 10 ^-3 to 1 part by weight per 100 parts by weight of water. This aqueous solution may contain inorganic salts, such as sodium sulfate, as a dyeing adjuvant. The temperature of the dye aqueous solution used for dyeing is about 20-80 degreeC normally, and the immersion time (dyeing time) in this aqueous solution is about 10-1,800 second normally.

The boric acid treatment after dyeing with a dichroic dye is performed by immersing the dyed polyvinyl alcohol-type resin film in boric acid containing aqueous solution. The amount of boric acid in boric acid containing aqueous solution is about 2-15 weight part normally per 100 weight part of water, Preferably it is about 5-12 weight part. When using iodine as a dichroic dye, it is preferable that this boric acid containing aqueous solution contains potassium iodide. The amount of potassium iodide in the boric acid-containing aqueous solution is usually about 0.1 to 15 parts by weight, preferably about 5 to 12 parts by weight, per 100 parts by weight of water. Immersion time in boric acid containing aqueous solution is about 60 to 1,200 second normally, Preferably it is about 150 to 600 second, More preferably, it is about 200 to 400 second. The temperature of the boric acid containing aqueous solution is 50 degreeC or more normally, Preferably it is 50-85 degreeC, More preferably, it is 60-80 degreeC.

The polyvinyl alcohol-based resin film after boric acid treatment is usually washed with water. The water washing process is performed by immersing the polyvinyl alcohol-type resin film processed by boric acid in water, for example. The temperature of water in a water washing process is about 5-40 degreeC normally, and immersion time is about 1-120 second normally. After water washing, a drying process is performed and a polarizing film is obtained. The drying treatment is usually performed using a hot air dryer or a far infrared heater. The temperature of a drying process is about 30-100 degreeC normally, Preferably it is 50-80 degreeC. The time of the drying treatment is usually about 60 to 600 seconds, preferably about 120 to 600 seconds.

In this manner, the polyvinyl alcohol-based resin film is subjected to uniaxial stretching, dyeing with a dichroic dye, and boric acid treatment to obtain a polarizing film. The thickness of this polarizing film is about 5-40 micrometers. In this invention, a cycloolefin resin film is laminated | stacked on at least one surface of this polarizing film, and it becomes a polarizing plate.

Cycloolefin resin is thermoplastic resin which has a unit of the monomer which consists of cyclic olefins (cycloolefin) like a norbornene and a polycyclic norbornene-type monomer, for example. The cycloolefin-based resin may be a hydrogenated product of the ring-opening polymer of the cycloolefin or the ring-opening copolymer using two or more cycloolefins, and may be an addition copolymer of a cycloolefin with a chain olefin or an aromatic compound having a vinyl group. It may be. It is also effective to introduce a polar group.

In the case of using a copolymer of a cycloolefin with a chain olefin or an aromatic compound having a vinyl group, examples of the chain olefin include ethylene and propylene. Examples of the aromatic compound having a vinyl group include styrene, α-methyl styrene, and nuclear alkyl. Substituted styrene, etc. are mentioned. In this copolymer, the unit of the monomer which consists of cycloolefin may be 50 mol% or less, for example, about 15-50 mol%.

In particular, in the case of using a terpolymer of a cycloolefin, a chain olefin, and an aromatic compound having a vinyl group, the unit of the monomer consisting of the cycloolefin may be a relatively small amount in this way. In such a terpolymer, the unit of the monomer which consists of linear olefins is about 5 to 80 mol% normally, and the unit of the monomer which consists of an aromatic compound which has a vinyl group is about 5 to 80 mol% normally.

As a commercially available thermoplastic cycloolefin resin, "Topas" sold by Ticona, Germany, "Aton" sold by JSR Co., Ltd., and Nippon Xeon Co., Ltd. "ZEONOR" and "ZEONEX", "Appel" sold by Mitsui Chemical Industries, Ltd., etc. (all are brand names). Such cycloolefin-based resin is formed into a film, but a known method such as a solvent casting method or a melt extrusion method is suitably used for film formation. The cycloolefin resin film formed into a film is also marketed, for example, "Esshina" and "SCA40" which are sold from Sekisui Kagaku Kogyo Co., Ltd., and "Zeonor film" sold by Optes Co., Ltd. Etc. (all are brand names).

The cycloolefin-based resin film may be stretched uniaxially or biaxially, so as to exhibit predetermined birefringence characteristics. The draw ratio in this case is about 1.1 to 5 times normally, Preferably it is 1.1 to 3 times.

The thickness of the cycloolefin-based resin film is preferably thin in terms of thinning and weight reduction of the liquid crystal display device. However, when the thickness is too thin, the strength is lowered and the workability is poor. On the other hand, when the thickness is too thick, the transparency or the weight of the polarizing plate is increased. Problems such as are likely to occur. Therefore, it is preferable that the thickness of a cycloolefin resin film is 20 micrometers or more, It is more preferable that it is 20-200 micrometers, It is especially preferable that it is 20-100 micrometers.

In the present invention, the cycloolefin-based resin film as described above is bonded to one side of the polarizing film to form a polarizing plate, but it is preferable to bond the same or different kinds of protective film to the other side of the polarizing film. When this polarizing plate is applied to a liquid crystal display device, it is bonded to a liquid crystal cell from the cycloolefin resin film side. As a protective film bonded to the other surface of a polarizing film, when using the film which consists of cycloolefin resin, this film may be extended | stretched or may not be extended | stretched. Moreover, as a kind of protective film different from a cycloolefin resin film, a cellulose acetate film, a polycarbonate film, an acrylic film, etc. can also be used.

The cellulose acetate-based film is a partial or complete acetate ester of cellulose, and examples thereof include a triacetyl cellulose film, a diacetyl cellulose film, and the like. As a commercially available triacetyl cellulose film, "Fujitag TD80", "Fujitag TD80UF" and "Fujitag TD80UZ" sold by Fuji Sash Film Co., Ltd., and "KC8UX2MW" sold by Konica Minolta Opto Co., Ltd. And "KC8UY" and the like (both trade names). The thickness of a cellulose acetate film is about 20-200 micrometers normally.

These protective films may be subjected to surface treatment such as antiglare treatment, hard coating treatment, antistatic treatment, antireflection treatment and the like on the surface opposite to the surface bonded to the polarizing film. Moreover, the coating layer containing a liquid crystalline compound, its high molecular weight compound, etc. may be formed.

The thing which bonded the cycloolefin resin film extended | stretched to one side of the polarizing film, and the cellulose acetate type film to the other side with an adhesive agent is mentioned as a preferable aspect.

The adhesive agent used for bonding a polarizing film and a cycloolefin resin film, and when bonding a protective film different from a cycloolefin resin film to one side of a polarizing film, the adhesive agent used for bonding a polarizing film and this protective film From the viewpoint of thinning the adhesive layer, it is preferable to be water-based, that is, one in which the adhesive component is dissolved in water or dispersed in water. For example, the composition using polyvinyl alcohol-type resin and a urethane resin as a main component is mentioned as a preferable adhesive agent.

When polyvinyl alcohol-based resin is used as the main component of the adhesive, the polyvinyl alcohol-based resin may be carboxyl-modified polyvinyl alcohol, acetoacetyl group-modified polyvinyl alcohol, methylol group-modified in addition to partially saponified polyvinyl alcohol or fully saponified polyvinyl alcohol. It may be a modified polyvinyl alcohol-based resin such as polyvinyl alcohol, amino group-modified polyvinyl alcohol. In this case, the aqueous solution of polyvinyl alcohol-type resin becomes an adhesive agent. The concentration of the polyvinyl alcohol-based resin in the adhesive is usually about 1 to 10 parts by weight, preferably 1 to 5 parts by weight based on 100 parts by weight of water.

In order to improve adhesiveness, it is preferable to add curable components, such as glyoxal and a water-soluble epoxy resin, or a crosslinking agent to the adhesive agent containing the aqueous solution of polyvinyl alcohol-type resin. The water-soluble epoxy resin is, for example, a polyamide obtained by reacting epichlorohydrin with a polyamide polyamine obtained by the reaction of a polyalkylene polyamine such as diethylenetriamine or triethylenetetramine with a dicarboxylic acid such as adipic acid. It may be an epoxy resin. Commercially available products of such polyamide epoxy resins include "Sumirez resin 650" and "Sumirez resin 675" sold by Sumitomo Chemical Co., Ltd., and "WS-525" sold by Nippon PMC. Etc. The addition amount of these curable components-a crosslinking agent is 1-100 weight part normally with respect to 100 weight part of polyvinyl alcohol-type resins, Preferably it is 1-50 weight part. When the addition amount is small, the effect of the adhesive improvement is small, whereas when the addition amount is large, the adhesive layer tends to be weak.

The method of bonding a cycloolefin resin film or other protective film to the polarizing film with an adhesive may be generally known, and for example, a casting method, a meyer bar coating method, a gravure coating method, a die coating method, and a dip coating method. The method of apply | coating an adhesive agent to the adhesive surface of a polarizing film and / or the film joined to it by the method, the spraying method, etc., and superimposing these two is mentioned. The casting method is a method in which a film, which is a coated object, is moved in a vertical direction, a generally horizontal direction, or an inclined direction between the two, while the adhesive is dipped on the surface and applied. After apply | coating an adhesive agent, a polarizing film and the film bonded to it are pinched by a nip roll etc., and are bonded together.

And in this invention, in order to improve the adhesiveness of a cycloolefin resin film and a polarizing film, corona discharge treatment is given to the surface of the side joined to the polarizing film of a cycloolefin resin film. Corona discharge treatment is a process of applying and discharging a high voltage between electrodes, and activating the resin film arrange | positioned between electrodes. The effect of the corona discharge treatment varies depending on the type of electrode, electrode spacing, voltage, humidity, type of resin film used, and the like. It is preferable.

When such a corona discharge treatment is given to a cycloolefin resin film, a fine powdery substance may generate | occur | produce. According to the infrared absorption spectrum analysis, this fine powdery substance was confirmed to be a carboxylic acid derivative, and is considered to be a degradation product of cycloolefin resin. In the corona discharge treatment, when the output intensity exceeds 800 W, it was found that such fine powdery substances are more likely to occur regardless of the accumulated dose. Thus, in the present invention, corona discharge treatment is performed at an output intensity of 800 W or less.

When the corona output strength at this time is 800 W or more, the fine powdery substance as described above is likely to occur, and if the long-term production is continued while the fine powdery substance is generated, the fine powdery substance accumulates and contaminates the process. In addition, it also leads to the appearance defect of the obtained polarizing plate. On the other hand, if the corona output intensity is too small, the corona discharge may become unstable, so the corona output intensity is preferably set to 100 W or more and 800 W or less.

In addition, when employing a triacetyl cellulose-based resin as a protective film to be bonded to the other side of the polarizing film, in order to increase the adhesiveness, corona discharge treatment, ultraviolet irradiation treatment, flame (flame) treatment, saponification to the adhesion surface Surface treatments, such as a treatment, can also be performed suitably. As a saponification process, the method of immersing in aqueous solution of alkalis, such as sodium hydroxide and potassium hydroxide, is mentioned.

After laminating a cycloolefin resin film to a polarizing film and laminating a protective film on the other side of a polarizing film as needed, a drying process is performed. Although drying process is performed by spraying hot air, for example, the temperature at this time is suitably selected in the range of about 40-100 degreeC, Preferably it is 60-100 degreeC. The drying time is about 20 to 1,200 seconds. The thickness of the adhesive bond layer after drying is about 0.001-5 micrometers normally, Preferably it is 0.01 micrometer or more, More preferably, it is 2 micrometers or less, More preferably, it is 1 micrometer or less. If the thickness of the adhesive layer is too large, the appearance of the polarizing plate tends to be poor.

After bonding, sufficient adhesive strength is obtained by curing at least half a day, usually several days or more at a temperature of room temperature or more. Preferred curing temperature is 30-50 degreeC, More preferably, it is 35-45 degreeC. When curing temperature becomes 50 degreeC or more, what is called a "strong winding" becomes easy to generate | occur | produce in roll winding state. In addition, the humidity at the time of curing may be any degree, and the relative humidity should just be in the range of 0% RH-about 70% RH. The curing time is usually 1 day to 10 days, preferably 2 day to 7 days.

As described above, a polarizing plate obtained by bonding a cycloolefin resin film to at least one side of a polarizing film containing polyvinyl alcohol-based resin is obtained. And the adhesive layer for bonding to a liquid crystal cell is formed in the surface of the cycloolefin resin film of this polarizing plate, and it can be set as the polarizing plate with an adhesive. Here, in order to improve the adhesiveness of a cycloolefin resin film and an adhesive, after performing a corona discharge process on the surface of a cycloolefin resin film, it is preferable to form an adhesive layer on it.

Corona discharge treatment in this case is also performed at an output intensity of 800 W or less. By employ | adopting the output strength of such a corona discharge process, generation | occurrence | production of the fine powdery substance derived from a cycloolefin resin film can be suppressed. Also in this case, the output of the corona discharge treatment is preferably set to 100 W or more.

The pressure-sensitive adhesive is also called a pressure-sensitive adhesive, and when pressed, is adhered to the surface of another substance. When the adhesive is peeled off from the surface to be adhered, the pressure-sensitive adhesive is a viscoelastic material that can be removed with almost no trace, provided that the adherend has only strength. For example, the adhesive which has a polymer, such as an acryl type and urethane type as a main component, can be used. In particular, an acrylic pressure-sensitive adhesive is preferably used from the viewpoint of transparency. The thickness of an adhesive layer is about 15-40 micrometers normally.

The formation of the pressure-sensitive adhesive layer is applicable to the method of applying a solution of the pressure-sensitive adhesive component containing a polymer as described above as a main component and installing it by drying, except that the pressure-sensitive adhesive layer is formed on an independent film as described above on the pressure-sensitive adhesive layer side. You may employ | adopt the method of bonding to the surface of the cycloolefin resin film to which the same corona discharge process was given.

<Example>

Hereinafter, although an Example demonstrates this invention still in detail, this invention is not limited by these examples. In the example,% and part which show content-usage-amount are a basis of weight unless it mentions specially.

Production Example 1 Production of Polarizing Film

A polyvinyl alcohol film having a thickness of 75 μm was uniaxially stretched by about 5 times with a mean polymerization degree of about 2,400 and a saponification degree of 99.9 mol% or more, and further immersed in pure water at 60 ° C. for 1 minute while maintaining a tension state. Then, it was immersed at 28 degreeC for 60 second in the aqueous solution whose weight ratio of iodine / potassium iodide / water is 0.05 / 5/100. Then, it was immersed at 72 degreeC for 300 second in the aqueous solution whose weight ratio of potassium iodide / boric acid / water is 8.5 / 8.5 / 100. Subsequently, the resultant was washed with pure water at 26 ° C. for 20 seconds, and then dried at 65 ° C. to obtain a polarizing film in which iodine was adsorbed and oriented to the polyvinyl alcohol resin.

Production Example 2 Preparation of Adhesive

3 parts of carboxyl group-modified polyvinyl alcohol ("Kurarefobal KL318" by Kuraray Co., Ltd.) and a water-soluble polyamide epoxy resin ("Sumirez resin 650" by Sumitomo Chemical Co., Ltd.) (solid content concentration) 30 parts of aqueous solution))) was added to obtain a polyvinyl alcohol adhesive.

Example 1

The stretched film of 73 micrometers in thickness which consists of norbornene-type resin was prepared, and the corona discharge process was given to one side. At this time, the corona output intensity was changed between 500 and 2,000 W, and the accumulated dose was changed between 2 and 11 kJ / m 2 to observe the presence or absence of fine powdery substance on the film surface.

Example 2

The protective film of thickness 80micrometer which consists of triacetyl cellulose which corona-treated surface of the stretched norbornene-type resin film obtained in Example 1 on one side of the polarizing film obtained in manufacture example 1, and surface saponification treatment on the other side. Was bonded through the polyvinyl alcohol adhesive prepared in Preparation Example 2, respectively, and dried for 5 minutes at a temperature of 50 to 80 ℃. Thereafter, curing was performed for 7 days in an environment of 40 ° C to obtain a polarizing plate. Next, the corona discharge process was performed to the norbornene-type resin film surface of this polarizing plate using the corona treatment apparatus similar to Example 1. At this time, the corona output intensity was changed between 500 and 2,000 W, and the accumulated dose was changed between 3 and 8 kJ / m 2, and the presence or absence of fine powdery substance on the surface of the film was observed.

The results of Examples 1 and 2 are collectively shown in the graph of FIG. 1. In the figure, the abscissa indicates corona output intensity and the ordinate indicates corona integrated irradiation dose, ○ indicates that the occurrence of fine powdery substance is not recognized, and x indicates that the occurrence of fine powdery substance is recognized. From this figure, it can be seen that in the region where the corona output intensity is 1,000 W or more, generation of fine powdery substance is recognized, whereas in the region of 800 W or less, generation of the fine powdery substance is not recognized regardless of the integrated irradiation amount.

After performing the corona discharge treatment according to Example 2, by applying an acrylic pressure-sensitive adhesive to the surface of the norbornene-based resin film, for example, or bonding an acrylic pressure-sensitive adhesive provided on an independent film, to a polarizing plate with an adhesive can do.

According to the present invention, when the corona discharge treatment is applied to the surface of the cycloolefin resin film, the output intensity is set to be less than or equal to a predetermined value, thereby eliminating contamination in the process due to the generation of fine powdery substance, and having a good appearance. It becomes possible to manufacture the polarizing plate with an adhesive.

Claims (6)

In bonding a cycloolefin resin film to at least one side of the polarizing film containing polyvinyl alcohol-type resin, and manufacturing a polarizing plate, it outputs 800 W or less to the surface of the side to bond to the polarizing film of the said cycloolefin resin film. Corona discharge treatment is performed by intensity | strength, and the said polarizing film is bonded together through an adhesive agent on the process surface, The manufacturing method of the polarizing plate characterized by the above-mentioned. The manufacturing method of the polarizing plate of Claim 1 in which the cycloolefin resin film is extended | stretched. The method for producing a polarizing plate according to claim 1, wherein the cycloolefin resin film has a thickness of 20 to 100 μm. The method for producing a polarizing plate according to claim 2, wherein the cycloolefin resin film has a thickness of 20 to 100 μm. A corona discharge treatment is performed on the surface of the cycloolefin resin film of the polarizing plate obtained by the method according to any one of claims 1 to 4 at an output strength of 800 W or less, and then an adhesive layer is formed on the treated surface. The manufacturing method of the polarizing plate with an adhesive characterized by the above-mentioned. The manufacturing method of the polarizing plate with an adhesive of Claim 5 whose adhesive is an acrylic adhesive.

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