KR20100088575A - Method for manufacturing a laminated film - Google Patents

Abstract

PURPOSE: A manufacturing method of a laminated film is provided to control the curve of a polarizer formed on one surface of a polarized light device using a polarizer protection film. CONSTITUTION: A manufacturing method of a laminated film comprises the following steps: forming a polarizer by laminating a polarizer protection film(3) after attaching a glue layer(2) on one side of a polarized light device(1); and applying another glue layer(4) to the other side of the polarized light device to laminate a release film(5). The water vapor permeability of one of the polarizer protection film and the release film is over 150 g/square meters in 24 hours.

Description

Manufacturing method of laminated film {METHOD FOR MANUFACTURING A LAMINATED FILM}

This invention relates to the manufacturing method of the laminated | multilayer film formed by laminating | stacking a polarizer protective film on one main surface of a polarizer via an adhesive bond layer, and laminating a release film on the other main surface of the said polarizer via an adhesive layer.

The manufacture of the polarizing plate which provided the transparent protective film (corresponding to a polarizer protective film) only on one surface of a polarizer is as follows. First, a process of obtaining (A) polarizer as a front process. Here, a long polyvinyl alcohol film is dyed, crosslinked, and stretched to obtain a polarizer.

Subsequently, the process of manufacturing (B) polarizing plate. Here, these films are crimped | bonded and bonded between a pair of rolls, interposing a water-soluble adhesive between a polarizer and a polarizer protective film (for example, a triacetyl cellulose resin film etc.). This laminated laminated body is dried and the polarizing plate in which the polarizer protective film was formed only in one surface is manufactured.

Subsequently, (C) bonding process of a release film and a surface protection film. The release film is bonded to the polarizer surface of a polarizing plate through an adhesive. For example, these films are crimped | bonded and bonded between a pair of rolls, interposing an adhesive between a polarizing plate and a release film. Subsequently, a surface protective film is bonded together through an adhesive on the polarizer protective film surface.

Here, an adhesive is coated previously on a release film and a surface protection film, and the adhesive coated on the release film is transferred to the polarizer side after peeling off a release film. It can adhere to a liquid crystal panel by the transferred adhesive. Moreover, even if it peels a surface protection film, the adhesive coated on the surface protection film is as it is formed in the surface protection film, and it is not substantially transferred to the polarizer protective film side. By the above process, the long sheet product which laminated | stacked the release film and the surface protection film on the polarizing plate is manufactured, it is wound up in roll shape, and is provided to the next process.

However, in the method of manufacturing said polarizing plate, after bonding a polarizer and a polarizer protective film with an adhesive agent, it is drying without laminating a release film. The polarizer protective film requires mechanical strength (elasticity) from the viewpoint of protecting the polarizer and improved handling, that is, has a resilient characteristic different from that of the polarizer. And when a polarizer and a polarizer protective film are adhesively laminated by an adhesive and dried, the polarizing plate (polarizer, adhesive agent, polarizer protective film) will bend from the difference of the said elasticity characteristic. Since the elongate polarizing plate film is dried, this curvature is remarkable in the width direction of the film. With respect to such a curved polarizing plate, it is difficult to bond a release film or the like in the next step, and improvement is required. In addition, when cutting | disconnecting in the sheet state of predetermined magnitude | size from raw material for a polarizing plate, and attaching to a liquid crystal panel, when the curvature of a polarizing plate is large, it is difficult to join to a liquid crystal panel.

In addition, when the polarizing plate bonded to the liquid crystal panel was a defective product, a rework process is performed and the polarizing plate is peeled off from the liquid crystal panel. At this time, if the adhesiveness between the pressure-sensitive adhesive transferred from the release film and the polarizer is weak, glue remains on the surface of the liquid crystal panel. do. As a result, it is necessary to remove the adhesive left behind, and improvement is required.

Japanese Patent Laid-Open No. 2003-303727

When a polarizer protective film is a polarizing plate formed only in one surface of a polarizer, since curvature is large, it is thought that the bonding precision to a liquid crystal panel becomes very bad.

This invention is made | formed in view of the above-mentioned situation, The objective is the lamination | stacking which the curvature of the polarizing plate in which a polarizer protective film was formed only in the one main surface of the polarizer can be suppressed, and the remnant does not generate | occur | produce in rework processing, It is providing the manufacturing method of a film.

In order to solve the said subject, as a result of earnestly examining, it came to complete the following this invention.

This invention is a manufacturing method of the laminated | multilayer film formed by laminating a polarizer protective film on one main surface of a polarizer through an adhesive bond layer, forming a polarizing plate, and laminating a release film on the other main surface of the said polarizer via an adhesive layer,

At least one of the polarizer protective film and the release film is 150 g / m 2 · 24h or more in an atmosphere of 40 ° C. and 90% RH, and the polarizer, the polarizer protective film, and the release film It has a structure characterized by having the process of drying after lamination | stacking.

According to this structure, since the polarizer, the polarizer protective film, and the release film in which the adhesive layer was formed are laminated | stacked, it is the structure dried, and the curvature of the polarizing plate after drying is small compared with the former. That is, by configuring both sides of a polarizer in a sandwich form with a polarizer protective film and a release film, it is thought that the shrinkage of the polarizer after drying was suppressed and curvature of the polarizing plate was suppressed.

Moreover, at least any one of the polarizer protective film formed on one main surface of a polarizer and the release film formed on the other main surface of a polarizer is 150 g / m <2> * 24h or more in 40 degreeC and 90% RH atmosphere. Since it is comprised, when drying after lamination | stacking, evaporation of moisture is favorable and a drying defect does not arise. As an example of a dry defect, after peeling 1, the peeling defect which cannot peel a release film, 2, the transfer defect which 3, an adhesive layer does not transfer to a polarizer side, and 3, a release film, it is bonded to a liquid crystal panel via an adhesive layer, Peeling defect from the polarizer of the adhesive layer at the time of peeling a polarizing plate from a liquid crystal panel for rework processing is illustrated. The test method of moisture permeability here conforms to JIS Z 0208, the moisture permeability test method of a moisture proof packaging material.

In the atmosphere of 40 degreeC and 90% RH, a water | moisture-permeability is 150 g / m <2> * 24h or more, for example, a triacetyl cellulose resin film is illustrated. When a polarizer protective film is a triacetyl cellulose resin film, as a release film, the film of less than 150 g / m <2> * 24h can be used as a release film, for example, in 40 degreeC and 90% RH atmosphere. . As these low moisture-permeable films, norbornene-type resin films, acrylic resin films, polyethylene resin films, polyethylene terephthalate resin films and the like are exemplified.

Moreover, in this invention, the structure whose moisture content of the said polarizer before laminating the said release film and the said polarizer protective film is 5 weight% or more and 40 weight% or less is preferable.

According to this structure, generation | occurrence | production of the external appearance defect of a polarizer can be prevented, and also the fall of the optical characteristic of a polarizer and the fall of adhesiveness of a polarizer protective film and a polarizer can be prevented. That is, when the moisture content of a polarizer is less than 5 wt%, a micro fault called a streak or a clinic tends to occur. If the moisture content of the polarizer is more than 40wt%, when the moisture is removed by heating through the polarizer protective film or the release film, the polarizer is in a steam heating state, so that the polarizer is damaged and receives optical properties (especially transmittance and polarization degree). This falls or the adhesiveness of a polarizer protective film and a polarizer falls. In addition, the moisture content was computed by the drying weight loss method by sampling a polarizer from the position 5 seconds before a release film and a polarizer protective film are laminated | stacked.

Moreover, in this invention, after the said polarizer protective film is laminated | stacked on one main surface of the said polarizer, there exists a structure which laminates the said release film on the other main surface of the said polarizer.

According to this structure, since the laminated body is comprised step by step, a laminated body can be comprised, maintaining the bonding precision to a polarizer satisfactorily.

Moreover, in this invention, the said laminated | multilayer has the structure which simultaneously laminates the said polarizer, the said polarizer protective film, and the said release film.

According to this structure, since a laminated body is comprised simultaneously, a manufacturing line space can be made small and as a lamination | stacking means, only a pair of roll is provided, and the initial investment of equipment becomes small.

It is preferable to form a coat layer beforehand on the polarizer side of the adhesive surface of a polarizer and an adhesive layer. This coating layer is performed for the protection of a polarizer or for improving adhesiveness with an adhesive. As a coating layer, the adhesive which has polyvinyl alcohol, an isocyanate, cyanoacrylate, aziridine, etc. as a main component is preferable.

According to this invention, the polarizer protective film can suppress the curvature of the polarizing plate provided only in the one main surface of a polarizer, and can provide the manufacturing method of the laminated | multilayer film which does not generate | occur | produce in the rework process.

BRIEF DESCRIPTION OF THE DRAWINGS The figure for demonstrating the structure of laminated | multilayer film.
2 is a diagram for explaining a method for producing a laminated film.
3 is a view for explaining a method for producing a laminated film of Comparative Example 1. FIG.

In this invention, a polarizing plate is comprised from the polarizer protective film which protects a polarizer and its surface. In the present invention, the polarizer protective film is formed only on one surface of the polarizer. As for a polarizing plate, the release film is formed in the polarizer side and comprises a laminated film, and the structure which a surface protection film is formed in the polarizer protective film side is illustrated. The release film is peeled off when attached to the liquid crystal panel.

(Configuration of Laminated Film)

The structure of a laminated | multilayer film and its manufacturing method are demonstrated using FIG. 1, FIG. In FIG. 1, the polarizer protective film 3 is formed on one side (upper side in FIG. 1) of the polarizer 1 via the adhesive bond layer 2, and also the surface protective film (through the adhesive layer 6) 7) is formed. The coat layer 1a is formed in the other surface (lower side in FIG. 1) of the polarizer 1, and the adhesive layer 4 and the release film 5 are formed through the coat layer 1a. In the polarizing plate of the structure of FIG. 1, the release film 5 is peeled off, the adhesive 4 of the release film 5 is transferred to the polarizer 1 side, and the polarizer 1 surface is interposed through this adhesive 4. It is comprised so that it may be arrange | positioned at the liquid crystal panel side.

(Production method)

In FIG.2 (a) and FIG.2 (b), the manufacturing method of the laminated | multilayer film of FIG. 1 is shown. First, the manufacturing method of FIG. 2 (a) is demonstrated. The polarizer 1 is manufactured by the manufacturing method of the laminated film mentioned later, and the coating layer 1a is formed in one side of the polarizer 1 for the adhesive improvement with the adhesive 4. In addition, the polarizer protective film 3 is prepared as a raw material 41 manufactured in advance and wound in a roll shape. First, the water-soluble adhesive agent is apply | coated to the polarizer 1 conveyed continuously by the coating device 10. FIG. The polarizer protective film 3 is laminated on the polarizer 1 with the applied adhesive layer interposed therebetween, and they are bonded while applying a predetermined pressure by the roll pair 20. One pair may be sufficient as the roll pair 20, and it may be comprised by two or more pairs, and it is designed according to the specification of a polarizing plate. As clamping pressure of the roll pair 20, the range of 0.05-0.5 Mpa is illustrated. Roll diameter and roll spacing are also designed according to the specification of a polarizing plate. In addition, a spring mechanism (not shown) may be connected to the roll pair 20 in order to relief the stress of the perpendicular | vertical direction with respect to a roll.

Subsequently, the release film 5 is adhere | attached on the other surface side (side in which the coat layer 1a is formed) of the polarizer 1 via the adhesive layer 4. The release film 5 is the structure in which the adhesive layer 4 was previously apply | coated and the peeling film 9 was provided in order to protect the adhesive, and is prepared as the raw material 51 wound in roll shape. And before the lamination with the polarizer 1, the peeling film 9 is peeled off, the adhesive layer 4 surface is laminated | stacked with respect to the coating layer 1a surface of the polarizer 1, and it is roll roll 22 They stick together while applying a predetermined pressure. The pair of rolls 22 may be one pair, or may be comprised by two or more pairs, and it is designed according to the specification of a polarizing plate. As clamping pressure of the roll pair 22, the range of 0.05-0.5 Mpa is illustrated. Roll diameter and roll spacing are also designed according to the specification of a polarizing plate. Moreover, a spring mechanism (not shown) may be connected to the roll pair 22 in order to relief the stress of the perpendicular | vertical direction with respect to a roll.

Subsequently, the laminated film in which the polarizer 1, the polarizer protective film 3, and the release film 5 were laminated is fed into the drying apparatus 30, and the moisture of the polarizer 1, the moisture of an aqueous adhesive, etc. are dried. . The drying apparatus 30 can apply a well-known drying apparatus. Since films (polarizer protective film 3, release film 5) are laminated on both sides so as to sandwich the polarizer 1 before drying, curvature of the polarizing plate at the time of drying is suppressed. Moreover, as dry conditions, it controls so that temperature, humidity, and drying time may be adjusted according to the specification of a polarizing plate, and the curvature of a polarizing plate may be suppressed. As temperature conditions, it is controlled in the range of 60-80 degreeC, as a humidity condition in the range of 25%-45%, and as a drying time in the range of 30 second-5 minutes.

Subsequently, the surface protection film 7 is laminated. The surface protection film 7 is the structure in which the adhesive layer 6 was previously apply | coated, the peeling film 8 was provided in order to protect the adhesive, and it is prepared as the raw material 71 wound in roll shape. And before laminating with the polarizer protective film 3, the peeling film 8 is peeled off, the adhesive layer 6 surface is laminated | stacked with respect to the polarizer protective film 3 surface, and predetermined | prescribed by the roll pair 24 While acting on the pressure of, they stick.

Subsequently, when the surface protection film 7 is laminated | stacked, it is wound in roll shape as the laminated | multilayer film raw material 100 which has a surface protection film. When the laminated | multilayer film raw material 100 which has this surface protection film is slit by predetermined width size, it moves to a slit process.

(Other Manufacturing Method)

Next, the manufacturing method of FIG.2 (b) is demonstrated. The difference from the manufacturing method of FIG. 2 (a) is that the polarizer 1, the polarizer protective film 3, and the release film 5 are laminated at the same time. Since these are laminated | stacked by the roll pair 26 simultaneously, compared with the manufacturing method of FIG. 2 (a), a manufacturing line can be made small and installation cost can be made low. One pair may be sufficient as this roll pair 26, and it may be comprised by two or more pairs, and it is designed according to the specification of a polarizing plate. As clamping pressure of the roll pair 26, the range of 0.05-0.5 Mpa is illustrated. Roll diameter and roll spacing are also designed according to the specification of a polarizing plate. In addition, a spring mechanism (not shown) may be connected to the roll pair 26 in order to relief the stress of the perpendicular | vertical direction with respect to a roll.

In the above process, the laminated | multilayer film raw material which has the produced surface protection film is packaged, and is transported to the next process site. On the other hand, when performing the next process at the same place, it is conveyed to the next process in the simple packaging or the state as it is.

(Example of Configuration and Manufacturing Method of Polarizing Plate)

A polarizing plate is obtained by bonding polarizer protective films, such as a TAC (triacetylcellulose) film and PET (polyethylene terephthalate) film, to one side of a polyvinyl alcohol-type film (polarizer), for example.

A polarizer is obtained by drying the polyvinyl alcohol (PVA) film which performed the dyeing, crosslinking, and extending | stretching process, for example. Moreover, it is preferable from the point of adhesion with an adhesive and the point of polarizer protection that a coating layer is apply | coated and formed in the surface side different from a polarizer protective film surface. As for a coat layer, the adhesive which has a polyvinyl alcohol, an isocyanate, a cyanoacrylate, an aziridine, etc. as a main component is preferable, for example.

(Example)

As shown in FIG.2 (b), the laminated | multilayer film of Example 1 is a 3-layer film structure obtained by laminating | stacking a polarizer protective film, a polarizer (PVA film), and a release film simultaneously, and drying after that. As a polarizer protective film, the triacetyl cellulose-type resin film (TD80UL by Fujifilm Corporation) of thickness 80micrometer was used. As the polarizer protective film and the adhesive for the polarizer, a PVA-based aqueous adhesive was used. As a release film, the polyester resin film (Cerafil made from Toray Corporation) of thickness 38micrometer was used. As the pressure-sensitive adhesive, an acrylic pressure-sensitive adhesive was used. The moisture content of the polarizer immediately before laminating a release film was 20 wt%. The water vapor transmission rate of the triacetyl cellulose resin film was 750 g / m 2 · 24h (based on the test method of JIS Z 0208). In addition, the water vapor transmission rate of the polyester-type resin film (release film) was 20g / m <2> * 24h (based on the test method of JIS Z 0208). The pressure of the roll pair was 0.1 MPa, and drying conditions were temperature 70 degreeC and drying time 2 minutes.

The laminated | multilayer film of Example 2 is obtained by laminating a release film after laminating | stacking a polarizer and a polarizer protective film as shown to Fig.2 (a), and continuing to dry. The structure of a film structure, an adhesive agent, and an adhesive is the same as the structure of Example 1, and the other drying and pressure conditions were made the same.

The laminated | multilayer film of Example 3 is obtained similarly to Example 1 except having made the moisture content of the polarizer just before laminating a release film into 10 wt%.

The laminated | multilayer film of Example 4 is obtained similarly to Example 1 except having made the moisture content of the polarizer just before laminating a release film into 35 wt%.

The laminated | multilayer film of Example 5 is obtained similarly to Example 1 except having made the moisture content of the polarizer just before laminating a release film into 5 wt%.

The laminated | multilayer film of Example 6 is obtained similarly to Example 1 except having made the water content of the polarizer immediately before laminating a release film into 45 wt%.

The laminated | multilayer film of Example 7 was obtained like Example 1 except having made the moisture content of the polarizer just before laminating a release film into 3 wt%.

(Comparative Example)

The laminated | multilayer film of the comparative example 1 is obtained by making a polarizer protective film and a polarizer adhere | attach as shown in FIG. 3, drying, and then sticking a release film to the side of a polarizer with an adhesive. The film structure was the same as the structure of Example 1, and also made drying and pressure conditions the same. The moisture content of the polarizer immediately before laminating a release film was 13 wt%.

The laminated | multilayer film of the comparative example 2 is obtained similarly to Example 1 except having used the norbornene-type resin film (Zeonoa made from Nippon Xeon company) of thickness 70micrometer as a polarizer protective film. The water vapor transmission rate of this norbornene-type resin film was 5 g / m <2> * 24h.

In Examples 1 to 7 and Comparative Examples 1 to 2, a polyester resin film (cerafil manufactured by Toray Corporation) having a thickness of 38 μm was used as the release film. The water vapor transmission rate of the polyester resin film (release film) was 20 g / m 2 · 24h (based on the test method of JIS Z 0208). The water vapor transmission rate of the triacetyl cellulose resin film of the polarizer protective film of Examples 1-7 and the comparative example 1 was 750g / m <2> * 24h (based on the test method of JIS Z 0208). As a polarizer protective film of Comparative Example 2, a norbornene-based resin film (Zenoa manufactured by Nippon Xeon Co., Ltd.) having a thickness of 70 µm was used, and the moisture-permeability of this norbornene-based resin film was 5 g / m 2 · 24h.

(Evaluation method and result)

Four corners of the polarizing plate in the case where each laminated film is cut into an A4 size (210 mm x 297 mm) so as to have a long side of the conveying direction, and the release film is peeled off and left on a flat surface so that the pressure-sensitive adhesive face is upward. Was measured by the vernier caliper, and the average value was computed and the curvature amount was calculated | required. The numerical value of curvature amount was made into the average value of n = 10. As a result, although the polarizing plates of Examples 1-7 were curved, curvature was smaller than the polarizing plate of Comparative Example 1. In the case of the comparative example 1, curvature became large cylinder shape.

Subsequently, the pool remaining test with respect to the glass of these polarizing plates was done. The release film was peeled from each laminated film, and the exposed adhesive layer was stuck to a glass plate, and left to stand for 30 minutes, and then the polarizing plate was peeled off from the glass plate. The peeling method peeled so that peeling force might be 3 N / 25mm and it peeled off in 180 degree directions. In this case, it was visually observed about the glue remaining on the glass surface of the adhesive. This test was carried out n = 10, and if there was no pool remaining 8 times out of 10 times, it was set as pool remaining "none". As a result, in the polarizing plates of Examples 1 to 7, there was no pool remaining on the glass surface, while in the polarizing plates of Comparative Examples 1 and 2, there was pool remaining on the glass surface. That is, from this result, in the rework process, in the case of the polarizing plates of Examples 1-7, since there is no pool remaining to a glass surface, a rework process can be performed. On the other hand, in the case of the polarizing plates of Comparative Example 1 and Comparative Example 2, glue remains on the glass surface is generated, and thus, the glue remaining adhesive must be removed during the rework treatment.

Moreover, the release film was peeled from each laminated film, and the external appearance evaluation of the polarizing plate was performed visually. This test was carried out n = 10, and when there was no appearance defect 8 times out of 10 times, it was set as appearance "good." As a result, the polarizing plates of Examples 1 to 5 in which the moisture content of the polarizer before laminating a release film and a polarizer protective film were in the range of 5 wt%-40 wt% were favorable polarizing plates without appearance defects. On the other hand, the polarizing plate of Example 7 in which the moisture content of the polarizer before laminating a release film and a polarizer protective film was less than 5 wt% had no problem as a product, but the stripe unevenness was confirmed.

The optical properties of the single transmittance and the degree of polarization were evaluated. The optical characteristics of the polarizing film were measured with a spectrophotometer (V7100 manufactured by Nippon Bunko Co., Ltd.) having an integrating sphere. A single transmittance and a polarization degree are shown by the Y value correct | amended visibility by the 2-degree field of view (C light source) of JISZ8701. The numerical value of single transmittance and polarization degree was made into the average value of n = 10. As a result, although the polarizing plate of Example 6 in which the moisture content of the polarizer before laminating a release film and a polarizer protective film was larger than 40 wt%, there was no problem as a product, but the fall of optical characteristic (single transmittance, polarization degree) was confirmed.

Table 1 shows the results of Examples 1 to 7, Comparative Example 1, and Comparative Example 2 described above.

Also in the above, although the structure of the polarizing plate has been demonstrated partially, generally, the following materials can be illustrated.

(Polarizer)

The treatment of dyeing, crosslinking and stretching of the polyvinyl alcohol-based film does not need to be performed separately, and may be performed simultaneously, or the order of each treatment may be arbitrary. Moreover, you may use the polyvinyl alcohol-type film which performed the swelling process as a polyvinyl alcohol-type film. Generally, a polyvinyl alcohol-based film is immersed in a solution containing iodine or a dichroic dye, adsorbed and dyed by adsorbing iodine or a dichroic dye, and drawn in a solution containing boric acid, boron, or the like. Uniaxially stretch by 2 to 7 times. After extending | stretching in the solution containing iodine or a dichroic dye, and also extending | stretching (double-stretching) in the solution containing a boric acid, a boron, etc., since orientation of an iodine becomes high and polarization degree property becomes favorable, it is especially preferable. .

As said polyvinyl alcohol-type polymer, what was saponified after superposing | polymerizing vinyl acetate, what copolymerized the copolymerizable monomers, such as a small amount of unsaturated carboxylic acid, unsaturated sulfonic acid, cationic monomer, with vinyl acetate, etc. Can be mentioned. The average degree of polymerization of the polyvinyl alcohol-based polymer is not particularly limited and any one can be used, but is preferably at least 1000, more preferably 2000 to 5000. In addition, the degree of saponification of the polyvinyl alcohol polymer is preferably 85 mol% or more, and more preferably 98 to 100 mol%.

Although the thickness of the polarizer manufactured is 5-80 micrometers in general, it is not limited to this, Moreover, also about the method of adjusting the thickness of a polarizer, it does not specifically limit, A conventional method, such as a tenter, roll extending | stretching or rolling, can be used. Can be. By adjusting the water content of the polarizer to 15wt% to 40wt%, the adhesion and appearance with the polarizer protective film can be improved.

Although the adhesion process of a polarizer and the transparent polarizer protective film which is a protective layer is not specifically limited, For example, the adhesive agent which consists of a vinyl alcohol type polymer, or vinyl alcohol type polymers, such as boric acid, boron, glutaraldehyde, melamine, oxalic acid, etc. It can carry out via the adhesive etc. which consist of at least from a water-soluble crosslinking agent. Such an adhesive layer is formed as an application dry layer of an aqueous solution. However, other additives, catalysts such as an acid, and the like can also be blended when the aqueous solution is prepared.

(Polarizer protection film)

A suitable transparent film can be used for the polarizer protective film provided on one side of a polarizer. For example, thermoplastic resins excellent in transparency, mechanical strength, thermal stability, moisture barrier properties, and isotropy are used. Specific examples of such thermoplastic resins include cellulose resins such as triacetyl cellulose, polyester resins, polyether sulfone resins, polysulfone resins, polycarbonate resins, polyamide resins, polyimide resins, polyolefin resins, and (meth) acrylic resins. , Cyclic polyolefin resin (norbornene-based resin), polyarylate resin, polystyrene resin, polyvinyl alcohol resin, and mixtures thereof. In addition, although the transparent protective film is bonded by the adhesive bond layer on one side of a polarizer, said coat layer is formed on the other side. One or more types of arbitrary appropriate additives may be contained in the transparent protective film. As an additive, a ultraviolet absorber, antioxidant, a lubricating agent, a plasticizer, a mold release agent, a coloring inhibitor, a flame retardant, a nucleating agent, an antistatic agent, a pigment, a coloring agent, etc. are mentioned, for example. Content of the said thermoplastic resin in a transparent protective film becomes like this. Preferably it is 50-100 weight%, More preferably, it is 50-99 weight%, More preferably, it is 60-98 weight%, Especially preferably, it is 70-97 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 may not be fully expressed.

Although the thickness of a polarizer protective film can be suitably determined, it is generally about 1-500 micrometers in terms of workability, thinness, etc., such as intensity | strength and handleability. 1-300 micrometers is especially preferable, and 5-200 micrometers is more preferable. The polarizer protective film is particularly suitable in the case of 5 to 150 mu m.

As a polarizer protective film, it is preferable to use at least any one selected from a cellulose resin, a polycarbonate resin, a cyclic polyolefin resin, and a (meth) acrylic resin.

The cellulose resin is an ester of cellulose and a fatty acid. Specific examples of such cellulose ester-based resins include triacetyl cellulose, diacetyl cellulose, tripropionyl cellulose, dipropionyl cellulose and the like. Among these, triacetyl cellulose is particularly preferable. Many products of triacetyl cellulose are commercially available, and are advantageous in terms of availability and cost. Examples of commercially available products of triacetyl cellulose include trade names "UV-50", "UV-80", "SH-8O", "TD-80U", "TD-TAC" and "UZ-TAC" manufactured by Fuji Film Co., Ltd .; "KC series" made by Konica Corporation. In general, these triacetyl cellulose has an in-plane retardation (Re) of approximately zero, but the thickness retardation (Rth) has a thickness of about 60 nm.

Moreover, the cellulose resin film with a small thickness direction retardation is obtained by processing the said cellulose resin, for example. For example, base films, such as polyethylene terephthalate, polypropylene, and stainless steel which coated solvents, such as cyclopentanone and methyl ethyl ketone, are bonded to a general cellulose film, and are heat-dried (for example, 3 to 80-150 degreeC). To about 10 minutes), and then peeling off the base film; Coating a solution obtained by dissolving norbornene-based resin and (meth) acrylic resin with a solvent such as cyclopentanone and methyl ethyl ketone is applied to a common cellulose resin film and dried by heating (for example, at about 80 to 150 ° C. for about 3 to 10 minutes). After that, the method of peeling a coating film, etc. are mentioned.

Moreover, as a cellulose resin film with a small thickness direction retardation, the fatty acid cellulose resin film which controlled fat substitution degree can be used. In the triacetyl cellulose generally used, although the degree of acetic acid substitution is about 2.8, preferably Rth can be made small by controlling the degree of acetic acid substitution to 1.8 to 2.7. Rth can be controlled small by adding plasticizers, such as dibutyl phthalate, p-toluenesulfonanilide, and acetyl triethyl citrate, to the said fatty acid substituted cellulose resin. The amount of the plasticizer added is preferably 40 parts by weight or less, more preferably 1 to 20 parts by weight, still more preferably 1 to 15 parts by weight based on 100 parts by weight of fatty acid cellulose resin.

As a specific example of cyclic polyolefin resin, Preferably it is norbornene-type resin. Cyclic olefin resin is a general term for resin superposed | polymerized using cyclic olefin as a polymerization unit, For example, Unexamined-Japanese-Patent No. 1-240517, Unexamined-Japanese-Patent No. 3-14882, and Unexamined-Japanese-Patent No. 3-122137. The resin described in the publication etc. can be mentioned. Specific examples include ring-opening (co) polymers of cyclic olefins, addition polymers of cyclic olefins, olefins and α-olefins such as ethylene and propylene, copolymers thereof (typically random copolymers), and unsaturated carboxylic acids and their And graft polymers modified with derivatives, and those hydrides. A norbornene-type monomer is mentioned as a specific example of cyclic olefin.

As cyclic polyolefin resin, various products are marketed. As a specific example, Nippon Xeon Kabushiki Kaisha brand name "Xeonex", "Zeonoa", JSR Kabushiki Kaisha brand name "Aton", TICONA company name "Topas", Mitsui Kagaku Kabushiki Kaisha brand name " APEL ”.

As (meth) acrylic-type resin, Tg (glass transition temperature) becomes like this. Preferably it is 115 degreeC or more, More preferably, it is 120 degreeC or more, More preferably, it is 125 degreeC or more, Especially preferably, it is 130 degreeC or more. When Tg is 115 degreeC or more, it can become the thing excellent in the durability of a polarizing plate. Although the upper limit of Tg of the said (meth) acrylic-type resin is not specifically limited, From a moldability viewpoint, Preferably it is 170 degrees C or less. From (meth) acrylic-type resin, the film whose in-plane phase difference Re and thickness direction phase difference Rth are almost zero can be obtained.

As (meth) acrylic-type resin, arbitrary appropriate (meth) acrylic-type resin can be employ | adopted within the range which does not impair the effect of this invention. For example, poly (meth) acrylic acid ester, such as polymethyl methacrylate, methyl methacrylate (meth) acrylic acid copolymer, methyl methacrylate (meth) acrylic acid ester copolymer, and methacrylic acid methyl-acrylic acid ester -(Meth) acrylic acid copolymer, (meth) acrylic acid methyl-styrene copolymer (MS resin, etc.), a polymer having an alicyclic hydrocarbon group [for example, methyl methacrylate-cyclohexyl copolymer, methacrylic Acid methyl- (meth) acrylic acid norbornyl copolymer, etc.] are mentioned. Preferably, poly (meth) acrylic-acid C1-6 alkyl, such as polymethyl (meth) acrylate, is mentioned. More preferably, methyl methacrylate resin which has methyl methacrylate as a main component (50-100 weight%, Preferably 70-100 weight%) is mentioned.

As a specific example of (meth) acrylic-type resin, For example, (Met) which has a ring structure in the molecule | numerator of Mitsubishi Rayon Co., Ltd. Acripet VH, Acripet VRL20A, and Unexamined-Japanese-Patent No. 2004-70296. A high Tg (meth) acrylic resin system obtained by acrylic resin, intramolecular bridge | crosslinking, or intramolecular cyclization reaction is mentioned.

As (meth) acrylic-type resin, you may use (meth) acrylic-type resin which has a lactone ring structure. It is because it has high mechanical strength by high heat resistance, high transparency, and biaxial stretching.

As (meth) acrylic-type resin which has a lactone ring structure, Unexamined-Japanese-Patent No. 2000-230016, Unexamined-Japanese-Patent No. 2001-151814, Unexamined-Japanese-Patent No. 2002-120326, Unexamined-Japanese-Patent No. 2002-254544 (Meth) acrylic-type resin which has a lactone ring structure as described in Unexamined-Japanese-Patent No. 2005-146084, etc. is mentioned.

As for the said polarizer protective film, a thing whose frontal phase difference is less than 40 nm and thickness direction phase difference is less than 80 nm is normally used. Front phase difference Re is represented by Re = (nx-ny) xd. Thickness direction phase difference Rth is represented by Rth = (nx-nz) xd. In addition, Nz coefficient is represented by Nz = (nx-nz) / (nx-ny) (However, the refractive index of the slow axis direction, the fast axis direction, and the thickness direction of a film is set to nx, ny, nz, respectively, and d (Nm) is taken as the thickness of a film. The slow axis direction is the direction of the maximum refractive index in the film plane. Moreover, it is preferable that a polarizer protective film is as free of water as possible. The film whose retardation value of the thickness direction is -90 nm-+75 nm is used preferably. By using the thing whose phase difference value Rth of such thickness direction is -90 nm-+75 nm, coloring (optical coloring) of the polarizing plate resulting from a transparent polarizer protective film can be almost eliminated. The thickness direction retardation value Rth is more preferably -80 nm to +60 nm, particularly -70 nm to +45 nm.

As long as the objective of this invention is not impaired, the polarizer protective film may perform the process for the purpose of a hard-coat process, an anti-reflective process, the prevention of sticking, a diffusion, an antiglare, etc. The hard coat treatment is performed for the purpose of preventing scratches on the surface of the polarizing plate, and the like, for example, a method of adding a cured film excellent in hardness, slipperiness, etc., by a suitable ultraviolet curable resin such as silicone, to the surface of the transparent protective film. It can be formed as.

The polarizing plate is provided with a pressure-sensitive adhesive layer for bonding with other members such as a liquid crystal panel. Although the adhesion layer is not specifically limited, It can form with the appropriate adhesive according to the prior art, such as an acryl type. The moisture absorption rate is low due to the prevention of foaming or peeling phenomenon due to moisture absorption, the reduction of optical characteristics due to thermal expansion difference, the prevention of warpage of the liquid crystal panel, and the formation of a high quality and durable image display device. It is preferable that it is an adhesion layer excellent in heat resistance. Moreover, it can be set as the adhesion layer etc. which contain microparticles | fine-particles and show light diffusivity. What is necessary is just to form an adhesion layer in a required surface as needed, and when mentioning the polarizing plate which consists of a polarizer and a polarizer protective film, for example, what is necessary is just to form an adhesion layer in one side or both surfaces of a polarizer protective film as needed.

(Release film)

The exposed surface of the pressure-sensitive adhesive layer is temporarily covered with a release film (sometimes referred to as a separator) for the purpose of preventing contamination thereof until it is practically provided. Thereby, contact with an adhesion layer can be prevented in a usual handling state. As the separator, except for the above thickness conditions, for example, a plastic film, a rubber sheet, a paper, a cloth, a nonwoven fabric, a net, a foam sheet, a metal foil, a suitable thin body such as a laminate thereof, or the like, may be a silicone-based material. And suitable ones according to the prior art, such as those coated with a suitable release agent such as long chain alkyl, fluorine or molybdenum sulfide.

The surface protection film is formed through the weak adhesive on the polarizing plate opposite to the surface in which this separator was provided. The main purpose is to prevent scratches, to prevent contamination. As a surface protection film, suitable thin films, such as a plastic film, a rubber sheet, paper, cloth, a nonwoven fabric, a net, a foam sheet, a metal foil, and those laminates, are silicone type, long chain alkyl type, fluorine type, and molybdenum sulfide as needed, for example. Conventional suitable things, such as those coat-processed with suitable peeling agents, such as these, can be used.

In the present invention, the salicylic acid ester compound, the benzophenol compound, the benzotriazole compound, the cyanoacrylate compound, nickel, and the like in the above-mentioned polarizer and polarizer protective film, and in each layer such as an adhesive layer. The thing which gave ultraviolet absorbing ability by methods, such as a process with ultraviolet absorbers, such as a complex salt type compound, may be sufficient.

The laminated | multilayer film by this invention can be used suitably for formation of image display apparatuses, such as a liquid crystal display device, an organic electroluminescence display, and a PDP.

1: polarizer
1a: coat layer
3: polarizer protective film
5: release film
7: surface protection film
10: applicator
20: roll pair
22: roll pair
24: roll pair
26: roll pair
30: drying device
100: laminated film raw material having a surface protective film

Claims (4)

It is a manufacturing method of the laminated | multilayer film formed by laminating a polarizer protective film on one main surface of a polarizer through an adhesive bond layer, forming a polarizing plate, and laminating a release film on the other main surface of the said polarizer via an adhesive layer,
At least one of the polarizer protective film and the release film is 150 g / m 2 · 24h or more in an atmosphere of 40 ° C. and 90% RH, and the polarizer, the polarizer protective film, and the release film It has a process to dry after laminating, The manufacturing method of the laminated | multilayer film characterized by the above-mentioned. The manufacturing method of the laminated | multilayer film of Claim 1 whose moisture content of the said polarizer before laminating the said release film and the said polarizer protective film is 5 wt% or more and 40 wt% or less. The said laminated | multilayer film manufacturing method of Claim 1 or 2 in which the said release film is laminated | stacked on the other main surface of the said polarizer after laminating | stacking the said polarizer protective film on one main surface of the said polarizer. The said laminated | multilayer is a manufacturing method of the laminated | multilayer film of Claim 1 or 2 which laminates the said polarizer, the said polarizer protective film, and the said release film simultaneously.

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