KR20160089867A - Polarizing film with double-sided pressure-sensitive adhesive layer, method for manufacturing the same and image display device - Google Patents

Abstract

The present invention relates to a polarizing film with a double-sided adhesive layer having an adhesive layer on double sides of the polarizing film installed to be nearest to a viewer-side in an image displaying device. The present invention relates to the polarizing film which is used in the image displaying device, and is installed to be nearest to the viewer-side. The polarizing film with the double-sided adhesive layer includes an A adhesive layer which is arranged in the viewer-side of the polarizing film, and a B adhesive layer which is arranged in the opposite side of the A adhesive layer. The A adhesive layer includes an SA_1 separator. The B adhesive layer includes a B separator. A storage modulus of the A adhesive layer is 0.02-0.3 MPa in 23°C. A curl quantity of the polarizing film with the adhesive layer is -10mm to +60mm.

Description

FIELD OF THE INVENTION [0001] The present invention relates to a polarizing film having a double-sided pressure-sensitive adhesive layer,

The present invention relates to a polarizing film with a double-sided pressure-sensitive adhesive layer having a pressure-sensitive adhesive layer on both sides of a polarizing film provided on the most viewer side in a polarizing film used in an image display apparatus, and a method of manufacturing the same. Further, the present invention relates to an image display apparatus in which the double-sided pressure-sensitive adhesive layer-attached polarizing film is disposed on the viewer side. Examples of the image display device include a liquid crystal display device, an organic EL (electroluminescence) display device, a PDP (plasma display panel), and an electronic paper.

The double-sided pressure-sensitive adhesive layer-containing polarizing film of the present invention has a pressure-sensitive adhesive layer on both sides of a polarizing film, and the pressure-sensitive adhesive layer on the viewer side includes, for example, an input device such as a touch panel, A transparent substrate such as glass, a plastic cover, or the like. On the other hand, the pressure-sensitive adhesive layer on the opposite side of the viewer side is applied to the display portion of the image display apparatus. The touch panel can be suitably used for a touch panel such as an optical system, an ultrasonic system, a capacitive system, and a resistive film system. Particularly, it is suitably used for a capacitive touch panel. The touch panel is not particularly limited, but is used in, for example, a mobile phone, a tablet computer, a portable information terminal, and the like.

It is indispensable to arrange polarizing elements on both sides of the liquid crystal cell from the image forming system in a liquid crystal display device or the like, and in general, a polarizing film is adhered. In order to adhere the polarizing film to the display portion side such as a liquid crystal cell, an adhesive is usually used. In such a case, there is an advantage that a drying process is not required to fix the polarizing film, and thus the pressure-sensitive adhesive is generally used as a polarizing film with a pressure-sensitive adhesive layer provided as a pressure-sensitive adhesive layer on one side of the polarizing film. A variety of polarizer films with a pressure-sensitive adhesive layer have been proposed (Patent Documents 1 and 2). In these pressure-sensitive adhesive layer-containing polarizing films, the pressure-sensitive adhesive layer side is applied to a display portion such as a liquid crystal cell.

On the viewer side of the polarizing film, on the other hand, a member such as an input device such as a touch panel, a cover glass, or a transparent substrate such as a plastic cover is provided. In general, the member is also bonded by a pressure-sensitive adhesive layer (Patent Document 3).

Japanese Patent Application Laid-Open No. 2004-170907 Japanese Patent Laid-Open No. 2006-053531 Japanese Patent Laid-Open No. 2002-348150

As in Patent Documents 1 and 2, the pressure-sensitive adhesive layer of the polarizing film attached with the pressure-sensitive adhesive layer is bonded to the display portion in the pressure-sensitive adhesive layer-attached polarizing film provided on the most viewer side of the polarizing film used in the image display apparatus. On the other hand, when a member such as a transparent substrate is provided on the visual side of the pressure-sensitive adhesive layer-attached polarizing film (on the most visible side), the polarizing film of the pressure-sensitive adhesive layer- A pressure sensitive adhesive sheet for a pressure sensitive adhesive sheet is prepared and joined as a pressure sensitive adhesive layer, and then a member such as a transparent gas is further bonded to the pressure sensitive adhesive layer. As described above, a plurality of steps are required to further join a member such as a transparent substrate to the polarizing film on the viewer's side most visually in the polarizing film used in the image display apparatus.

Patent Documents 1 and 2 disclose, as the polarizing film with a pressure-sensitive adhesive layer, one having a pressure-sensitive adhesive layer on both sides of a polarizing film (full lamination: polarizing film with double-sided pressure-sensitive adhesive layer). However, when the double-sided pressure-sensitive adhesive layer-attached polarizing film is adhered to an adherend (a member such as a transparent substrate or the like on the visual side and a display portion on the opposite side), bubbles tend to be entrained at the end of the bonding surface. Not enough, yield was not enough. Therefore, in the polarizing film with double-sided pressure-sensitive adhesive layer, it is required to simplify the process, improve the workability, and improve the yield.

In addition, the surface of the member such as the cover glass, such as the transparent substrate, is stepped by the printing ink. Therefore, when the member having the stepped surface and the other member are bonded by the adhesive layer, it is required that the adhesive layer absorbs the step, and the adhesive layer follows the step so that there is no gap between the members. As an index of the pressure-sensitive adhesive layer relating to the step, it is preferable to satisfy the followability at a value of the step difference (%): (step difference / pressure-sensitive adhesive layer thickness) expressed by the step (占 퐉) . The stepwise absorbency is required to be about 20%. In recent years, the requirement of the level difference absorbency is as high as 30%. Generally, in order to absorb the step, the elastic modulus of the pressure-sensitive adhesive layer may be lowered and smoothened. However, if the pressure-sensitive adhesive layer is made soft, the workability is poor and the pressure-sensitive adhesive is contaminated to a large extent.

On the other hand, when the pressure-sensitive adhesive layer of the double-sided pressure-sensitive adhesive layer-attached polarizing film (to which a member such as a transparent substrate is bonded) is made rigid, the step difference absorbency is lowered by full lamination, .

Therefore, the present invention relates to a polarizing film with a double-sided pressure-sensitive adhesive layer having a pressure-sensitive adhesive layer on both sides of a polarizing film provided on the viewer's side most visually in a polarizing film used in an image display apparatus, A pressure-sensitive adhesive layer-coated polarizing film, and a process for producing the same.

It is still another object of the present invention to provide an image display apparatus having the double-sided pressure-sensitive adhesive layer-containing polarizing film.

As a result of intensive investigations to solve the above problems, the present inventors have found out the following polarizing film with double-sided pressure-sensitive adhesive layer, and have completed the present invention.

That is, the present invention has a polarizing film provided on the most viewer side of a polarizing film used in an image display apparatus, a pressure-sensitive adhesive layer A disposed on the viewer side of the polarizing film, and a pressure-sensitive adhesive layer B disposed on the opposite side of the pressure- , A separator SA ₁ on the pressure-sensitive adhesive layer A, and a separator SB on the pressure-sensitive adhesive layer B,

The pressure-sensitive adhesive layer (A) has a storage elastic modulus at 23 캜 of 0.02 to 0.3 MPa,

The double-sided pressure-sensitive adhesive layer-containing polarizing film was placed on a horizontal plane so that the curled rectangular face was located on the lower side with respect to the cut rectangular product of 300 mm in the absorption axis direction of the polarizing film and 250 mm in the direction perpendicular to the absorption axis The curl amount measured by placing the separator SB side on the horizontal plane so that the separator SB side is on the horizontal plane is + and the curl measured by placing the separator SA ₁ on the horizontal plane so as to be the lower side) is -10 mm to +60 mm Sensitive adhesive layer with a double-sided pressure-sensitive adhesive layer.

In the double-sided pressure-sensitive adhesive layer-containing polarizing film, the curl amount is preferably +2 mm to +30 mm.

In the double-sided pressure-sensitive adhesive layer-containing polarizing film, it is preferable that the thickness of the separator SA ₁ is 50 μm or more and the thickness of the separator SB is 30 to 55 μm.

In the double-sided pressure-sensitive adhesive layer-containing polarizing film, the peeling force a ₁ of the separator SA ₁ is preferably higher than the peeling force b of the separator SB.

Further, the present invention is a method for producing the polarizing film with double-sided pressure-sensitive adhesive layer,

Side adhesive layer B having a polarizing film and a pressure-sensitive adhesive layer B provided on the most viewer side of the polarizing film used in the image display apparatus and having the separator SB in the pressure-sensitive adhesive layer B,

A one-side separator over the pressure-sensitive adhesive layer A having a separator SA ₁ the storage modulus of 23 ℃ is 0.02 to 0.3MPa pressure-sensitive adhesive layer A above,

(1) of joining the pressure-sensitive adhesive layer A of the single-sided separator-attached pressure-sensitive adhesive layer A with a roll-to-roll process so that the pressure-sensitive adhesive layer A of the single-sided pressure-sensitive adhesive layer A with the single-sided separator is disposed on the polarizing film opposite to the side on which the pressure- Sensitive adhesive layer having a double-sided pressure-sensitive adhesive layer.

In the method for producing the double-sided pressure-sensitive adhesive layer polarizing film over the one-side separator over the pressure-sensitive adhesive layer A is the pressure-sensitive adhesive layer A side of the separator SA ₁ on the side of both side separator over the pressure-sensitive adhesive layer with a separator SA ₂ on the other side A of (A) of separating the separator SA ₂ from the separator SA ₂ ,

To the separator peeling force of SA ₁ a _1, the separator, the peeling strength of SA ₂ a _2, b release force of the separator SB satisfy the relationship a _1> a ₂ ≥b preferred.

In the method for producing the double-sided pressure-sensitive adhesive layer over the polarizing films, the peeling strength of the separator ₁ a SA _1, SA ₂ of the separator peeling force a _2, b release force of the separator SB is a _1> 1.5a ₂ ≥1.5b Is satisfied.

In the step (1) of joining with the roll-to-roll in the method for producing a polarizing film with double-sided pressure-sensitive adhesive layer,

It is preferable to control the ratio (T1 / T2) of the tension T1 of the single-sided separator-attached pressure-sensitive adhesive layer A and the tension T2 of the single-sided pressure-sensitive adhesive layer B to 0.8 or more.

The method for producing a polarizing film with double-sided pressure-sensitive adhesive layer,

(B) and (c) of peeling the separator SA ₁ from the obtained double-sided pressure-sensitive adhesive layer-

(2) joining the curl adjusting separator SA ₁ 'to the pressure-sensitive adhesive layer A of the polarizing film with the separator SA ₁ peeled off on the double-sided pressure-sensitive adhesive layer with the roll-to-roll method.

In the step (2) of joining with the roll-to-roll in the production method of the double-sided pressure-sensitive adhesive layer-containing polarizing film,

To the curl adjustment separator SA ₁ 'tension T3 and the separator SA ₁ ratio (T3 / T4) with T4 tension of a polarizing film over both sides of the pressure-sensitive adhesive layer is peeled off in a controlled less than 0.8 are preferred.

The method for producing a polarizing film with double-sided pressure-sensitive adhesive layer,

A step (c) of cutting the obtained double-sided pressure-sensitive adhesive layer-containing polarizing film to an arbitrary size, and a step (d) of cutting the end of the polarized film with the double-sided pressure-sensitive adhesive layer cut off.

Further, the present invention is an image display apparatus having at least one double-sided pressure-sensitive adhesive layer-containing polarizing film,

Sensitive adhesive layer-side polarizing film provided on the most viewer side of the polarizing film used in the image display apparatus is obtained by removing the separator SA ₁ and the separator SB from the polarizing film with double-side pressure-sensitive adhesive layer,

Wherein the pressure-sensitive adhesive layer (A) of the double-sided pressure-sensitive adhesive layer-containing polarizing film is placed on the viewer side and the pressure-sensitive adhesive layer (B) is on the display portion side.

In an image display apparatus, a member such as a transparent glass such as a cover glass may be disposed closer to the viewing side than the viewer side polarizing film. Conventionally, the pressure-sensitive adhesive layer and the above member are laminated on the viewer side of the polarizing film. However, the pressure-sensitive adhesive layer-containing polarizing film of the present invention has the pressure-sensitive adhesive layer which is bonded to one side of the polarizing film to a member such as a transparent substrate, Sensitive adhesive layer having a pressure-sensitive adhesive layer that adheres to a display portion, and the pressure-sensitive adhesive layer is also provided on the viewing side of the polarizing film, so that the process can be simplified in the production of an image display device. Further, according to the polarizing film in which the pressure-sensitive adhesive layer is formed on both surfaces in advance, by processing the polarizing film to a predetermined size, productivity and quality can be improved.

The polarization film over both sides of the pressure-sensitive adhesive layer of the present invention, it is provided with a respective separator SA _1, a separator SB in the two-sided pressure-sensitive adhesive layer A and adhesive layer B, so the amount of curl or the like art separator SA ₁ and a separator SB predetermined amount Respectively. By controlling the curl amount in this manner, it is possible to suppress the phenomenon in which bubbles are entrained at the ends of the bonding surface when bonding the polarizing film with double-stick adhesive layer to the display portion and further joining members such as a transparent substrate, , Thereby improving the yield.

In the double-sided pressure-sensitive adhesive layer-containing polarizing film of the present invention, the storage elastic modulus of the pressure-sensitive adhesive layer A (pressure-sensitive adhesive layer for bonding a member such as a transparent glass or the like such as a cover glass) disposed on the viewer side of the polarizing film is controlled to a predetermined range Therefore, there is no problem such as contamination of the pressure-sensitive adhesive and the handling property is good. Further, according to the pressure-sensitive adhesive layer in which the storage elastic modulus is controlled in a predetermined range, the lowering of the level difference absorbability caused by the full lamination can be suppressed and the durability (inhibition of foaming) with respect to reliability can be suppressed.

Further, when the pressure-sensitive adhesive layer A is formed by a multiple pressure-sensitive adhesive layer having at least two pressure-sensitive adhesive layers, even when a member such as a transparent substrate is a member having a step on its surface, Bonding can be performed. The multi-layered pressure-sensitive adhesive layer can be bonded to the multi-layered pressure-sensitive adhesive layer without voids in accordance with the above step even when the member such as a transparent substrate has a step on its surface.

The double-sided pressure-sensitive adhesive layer-containing polarizing film of the present invention can be produced, for example, by a process of joining a single-sided pressure-sensitive adhesive layer B-containing polarizing film having a pressure-sensitive adhesive layer A- By the process of joining with the roll-to-roll process, the handling property can be improved to suppress the stain of the pressure-sensitive adhesive, and further, the workability of the resulting polarizing film with double-stick adhesive layer can be improved.

Further, in the step of joining with the roll-to-roll process, the curl amount of the obtained double-sided pressure-sensitive adhesive layer-containing polarizing film is controlled to be a predetermined amount by controlling the respective tensile forces of the single-sided separator-attached pressure-sensitive adhesive layer A and the single- . In addition, in the double-sided pressure-sensitive adhesive layer-containing polarizing film, the amount of curl of the double-sided pressure-sensitive adhesive layer-containing polarizing film can be controlled to be a predetermined amount by replacing the separator SA ₁ .

1A is a cross-sectional view schematically showing an embodiment of a double-sided pressure-sensitive adhesive layer-attached polarizing film of the present invention.
Fig. 1B is a sectional view schematically showing one embodiment of the double-sided pressure-sensitive adhesive layer-attached polarizing film of the present invention.
2A is a cross-sectional view schematically showing the curl amount of the double-sided pressure-sensitive adhesive layer-attached polarizing film of the present invention.
2B is a cross-sectional view schematically showing the curl amount of the polarizing film with double-sided pressure-sensitive adhesive layer of the present invention.
Fig. 3 is a conceptual diagram schematically showing a state in which an image display apparatus and a member such as a transparent substrate are bonded to each other via the double-sided pressure-sensitive adhesive layer-attached polarizing film of the present invention.
4A is a cross-sectional view schematically showing an embodiment of an image display apparatus.
4B is a cross-sectional view schematically showing one embodiment of the image display apparatus.
4C is a cross-sectional view schematically showing an embodiment of the image display apparatus.
5 is a cross-sectional view schematically showing an embodiment of a pressure-sensitive adhesive layer A with a double-side separator.
Fig. 6 is a cross-sectional view schematically showing one embodiment of the step (1) of joining with the roll-to-roll in the method for producing a polarizing film with double-sided pressure-sensitive adhesive layer of the present invention.
7 is a cross-sectional view schematically showing one embodiment of a roll-to-roll bonding step (2) using a curling-use separator in the method for producing a polarizing film with double-sided pressure-sensitive adhesive layer according to the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the double-sided pressure-sensitive adhesive layer-attached polarizing film of the present invention will be described in detail with reference to the drawings. However, the present invention is not limited to the embodiments shown in the drawings.

1A and 1B, the double-sided pressure-sensitive adhesive layer-containing polarizing film 10 (10 ') of the present invention comprises a polarizing film 1 and a pressure-sensitive adhesive layer A and a pressure- B. In the double-sided pressure-sensitive adhesive layer-containing polarizing film 10 (10 ') of the present invention, the separator SA ₁ is provided in the pressure-sensitive adhesive layer A and the separator SB is provided in the pressure- In addition, the separator SA ₁ may be used as a color separator for adjustment to be described later SA ₁ '.

1A, a case where the pressure-sensitive adhesive layer A is one layer is exemplified. However, the pressure-sensitive adhesive layer A is a pressure-sensitive adhesive layer in which a first pressure-sensitive adhesive layer (a) and a second pressure-sensitive adhesive layer (b) Layer. 1B shows a case where the pressure-sensitive adhesive layer A is a multilayer of two layers of the first pressure-sensitive adhesive layer (a) and the second pressure-sensitive adhesive layer (b). The number of layers of the pressure-sensitive adhesive layer A is not limited, but usually about five layers can be formed. The number of layers of the pressure-sensitive adhesive layer is preferably 2 to 4 layers, more preferably 2 to 3 layers. The multiple pressure-sensitive adhesive layer is formed by directly adhering each layer.

The pressure-sensitive adhesive layer having a different composition is used for the pressure-sensitive adhesive layer adjacent to the pressure-sensitive adhesive layer, but a pressure-sensitive adhesive layer having the same composition can be used for the pressure-sensitive adhesive layer not adjacent to the pressure- In Fig. 1B, the first pressure-sensitive adhesive layer (a) and the second pressure-sensitive adhesive layer (b) have different compositions. In the case where the first pressure sensitive adhesive layer (a), the second pressure sensitive adhesive layer (b) and the third pressure sensitive adhesive layer (c) are used as the pressure sensitive adhesive layer A from the outermost surface side (viewing side) The second pressure-sensitive adhesive layer (b) has a different composition, and the second pressure-sensitive adhesive layer (b) and the third pressure-sensitive adhesive layer (c) have different compositions. The first pressure sensitive adhesive layer (a), the second pressure sensitive adhesive layer (b) and the third pressure sensitive adhesive layer (c) may have different compositions, but the first pressure sensitive adhesive layer (a) .

2A and 2B are cross-sectional views schematically showing curl amounts of the double-sided pressure-sensitive adhesive layer-containing polarizing film 10 (10 ') of the present invention. The measurement of the curl amount is carried out for a rectangular piece of polarized film 10 (10 ') having a double-sided pressure-sensitive adhesive layer cut out at a distance of 300 mm in the absorption axis direction of the polarizing film 1 and 250 mm in the direction orthogonal to the absorption axis. As shown in Figs. 2A and 2B, the measurement of the curl amount is carried out on a horizontal plane so that the curl is convex downward. In addition, the curl amount is measured by placing the separator SB side of the double-sided pressure-sensitive adhesive layer-containing polarizing film 10 (10 ') on the horizontal surface so as to be on the lower side, as shown in Fig. 2A, , And the curl amount h measured with the side of the separator SA ₁ (SA ₁ ') on the horizontal surface being the lower side is indicated as " - ". The curl amount h is the distance (mm) of the longest point from the horizon of the four corners of the rectangular object.

The curl amount h is controlled to -10 mm to +60 mm from the viewpoints of workability and yield. The curled amount h is preferably + in the range of +2 mm to +30 mm, more preferably +5 mm to +20 mm, in terms of workability and yield, as shown in FIG. 2A.

 <Pressure-sensitive adhesive layer>

Hereinafter, the pressure-sensitive adhesive layer A and the pressure-sensitive adhesive layer B of the present invention will be described. Further, the pressure-sensitive adhesive layer A and the pressure-sensitive adhesive layer B are all "transparent", and the haze value measured with a thickness of 25 μm is 2% or less. The haze value is preferably 0 to 1.5%, more preferably 0 to 1%.

 &Lt; Thickness of pressure-sensitive adhesive layer &

The total thickness of the pressure-sensitive adhesive layer A is preferably 5 占 퐉 to 1 mm. The total thickness of the pressure-sensitive adhesive layer A can be appropriately designed in accordance with the portion to which the pressure-sensitive adhesive layer A is applied. The total thickness of the pressure-sensitive adhesive layer A is preferably 10 占 퐉 to 500 占 퐉, more preferably 20 占 퐉 to 300 占 퐉.

Further, when the pressure-sensitive adhesive layer A is a multiple pressure-sensitive adhesive layer having the first pressure-sensitive adhesive layer (a) and the second pressure-sensitive adhesive layer (b), the thickness of each pressure-sensitive adhesive layer is preferably 3 to 200 μm, more preferably 5 to 150 μm More preferably 10 to 100 mu m.

1B, when the pressure-sensitive adhesive layer A has a two-layer structure of the first pressure-sensitive adhesive layer (a) and the second pressure-sensitive adhesive layer (b), the thickness of the first pressure- More preferably 5 to 100 占 퐉, further preferably 10 to 75 占 퐉. The thickness of the second pressure-sensitive adhesive layer (b) is preferably 10 to 300 占 퐉, more preferably 20 to 150 占 퐉, further preferably 50 to 100 占 퐉. The difference between the thickness of the first pressure-sensitive adhesive layer (a) and the thickness of the second pressure-sensitive adhesive layer (b) is preferably 20 to 270 占 퐉, more preferably 30 to 200 占 퐉, from the viewpoint of level difference absorbability and processability.

On the other hand, the thickness of the pressure-sensitive adhesive layer B is generally from 1 to 500 탆, preferably from 5 to 200 탆, particularly preferably from 10 to 100 탆.

 <Storage modulus of pressure-sensitive adhesive layer>

The pressure-sensitive adhesive layer (A) has a storage elastic modulus at 23 캜 of 0.02 to 0.3 MPa. By the pressure-sensitive adhesive layer A whose storage elastic modulus is controlled in such a range, the pressure-sensitive adhesive can be prevented from being contaminated and the workability of bonding to the transparent substrate can be improved, thereby improving the yield. The storage elastic modulus is preferably 0.02 to 0.4 MPa, more preferably 0.03 to 0.3 MPa, further more preferably 0.05 to 0.1 MPa. The control of the storage elastic modulus of the pressure-sensitive adhesive layer A is also preferable for satisfying the level difference absorbency.

 &Lt; Peel strength of pressure-sensitive adhesive layer >

The pressure-sensitive adhesive layer A is provided with a separator SA ₁ (SA ₁ '), and the pressure-sensitive adhesive layer B is provided with a separator SB. The peel force a ₁ of the separator SA ₁ (SA ₁ ') relative to the pressure-sensitive adhesive layer A is preferably 0.01 to 5 N / 50 mm, more preferably 0.05 to 2 N / 50 mm, further preferably 0.1 to 1 N / desirable. The separating force b of the separator SB relative to the pressure-sensitive adhesive layer B is preferably 0.01 to 5 N / 50 mm, more preferably 0.05 to 2 N / 50 mm, further preferably 0.1 to 1 N / 50 mm.

It is also preferable that the peeling force a ₁ of the separator SA ₁ (SA ₁ ') is adjusted to be higher than the peeling force b of the separator SB, because it is first bonded to the display panel. The difference between the peeling force a ₁ of the separator SA ₁ (SA ₁ ') and the peeling force b of the separator SB is preferably 0.01 to 2 N / 50 mm, more preferably 0.02 to 1 N / 50 mm, Do.

The measurement of the storage elastic modulus and the peeling force is based on the description of the examples.

As shown in FIG. 3, the double-sided pressure-sensitive adhesive layer-attached polarizing film of the present invention is obtained by removing the separator SA ₁ (SA ₁ ') and the separator SB. The polarizing film related to the double-sided pressure-sensitive adhesive layer-containing polarizing film of the present invention is applied as a polarizing film provided on the most viewer side in a polarizing film used in an image display apparatus. The pressure-sensitive adhesive layer A of the double-sided pressure-sensitive adhesive layer-containing polarizing film of the present invention is disposed on the viewer side of the image display apparatus and bonded to the member C such as a transparent substrate. In the polarizing film (1), the pressure-sensitive adhesive layer (B) is disposed on the opposite side of the pressure-sensitive adhesive layer (A) and bonded to the display portion (D).

Examples of the member C include an input device such as a touch panel that is applied on the visual side of the image display device, a transparent glass such as a cover glass and a plastic cover, and the like.

The display portion D forms a part of the image display device together with at least one polarizing film 1 and is used for a liquid crystal display device, an organic electroluminescence (EL) display device, a PDP (plasma display panel) . As the display portion D, a liquid crystal display device having the liquid crystal layer 5 used together with the polarizing film 1 can be suitably used. Sectional views schematically showing typical embodiments of an image display apparatus (liquid crystal display apparatus) to which the pressure-sensitive adhesive layer-coated polarizing film of the present invention is applied are shown in Figs. 4A to 4C. In the image display device (liquid crystal display device) of Figs. 4A to 4C, the upper polarizing film 1 is located on the most visible side.

The image display device (liquid crystal display device) shown in Fig. 4A is constituted of the cover glass C / pressure-sensitive adhesive layer A / polarizing film 1 (visible side) / pressure- sensitive adhesive layer 2 (B) / antistatic layer 3 / glass substrate 4 A liquid crystal layer 5, a driving electrode 6, a glass substrate 4, a pressure-sensitive adhesive layer 2, and a polarizing film 1, as shown in Fig. The antistatic layer 3 and the driving electrode 6 can be formed of a transparent conductive layer. The antistatic layer 3 may be formed arbitrarily.

The image display device (liquid crystal display device) shown in Fig. 4B is a case in which the transparent conductive layer is used as an electrode application of a touch panel (in-cell type touch panel), and the cover glass C / the pressure sensitive adhesive layer A / polarizing film 1 / Adhesive layer 2 (B) / antistatic layer and sensor layer 7 / glass substrate 4 / liquid crystal layer 5 / driving electrode / sensor layer 8 / glass substrate 4 / 2) / polarizing film (1). The antistatic layer and sensor layer 7 and the drive electrode and sensor layer 8 can be formed of a transparent conductive layer.

The image display device (liquid crystal display device) shown in Fig. 4C is a case where the transparent conductive layer is used as an electrode application of a touch panel (on-cell type touch panel), and the cover glass C / the pressure sensitive adhesive layer A / the polarizing film 1 / (2) (B) / antistatic layer and sensor layer 7 / sensor layer 9 / glass substrate 4 / liquid crystal layer 5 / driving electrode 6 / glass substrate 4 / ) / Polarizing film (1). The antistatic layer and the sensor layer 7, the sensor layer 9, and the driving electrode 6 can be formed of a transparent conductive layer.

As the polarizing film, it is generally used to have a transparent protective film on one side or both sides of the polarizer. A functional layer such as a hard coating layer may be formed on the transparent protective film in the polarizing film. In addition, an optical film used for forming an image display device such as a liquid crystal display device or an organic EL display device is suitably used for the image display device. Examples of the optical film include a liquid crystal display device such as a reflection plate or a transflective plate, a retardation plate (including a wave plate of 1/2 or 1/4), an optical compensation film, a time compensation film, And the like can be used as the optical layer. In addition to being usable as an optical film alone, they can be laminated to the above polarizing film in practical use and used in one layer or two or more layers.

4A to 4C, the pressure-sensitive adhesive layer 2 is disclosed for bonding to another member such as a liquid crystal cell (glass substrate). The pressure-sensitive adhesive layer (2) on the viewer side (upper side) of the liquid crystal cell is applied as the pressure-sensitive adhesive layer (B). The pressure-sensitive adhesive layer (2) can be appropriately selected from a variety of pressure-sensitive adhesives comprising, as base polymers, polymers such as acrylic polymers, silicone polymers, polyesters, polyurethanes, polyamides, polyethers, In particular, it is preferable that it exhibits excellent optical transparency, appropriate wettability, cohesiveness and adhesive property such as an acrylic pressure-sensitive adhesive, and excellent weather resistance and heat resistance.

A liquid crystal display device generally includes a liquid crystal cell (constitution of a glass substrate / liquid crystal layer / glass substrate), a polarizing film disposed on both sides thereof, and a lighting circuit or the like, . As the liquid crystal cell, for example, any type of TN type, STN type, pi type, VA type, IPS type and the like can be used. In addition, a suitable liquid crystal display device such as a backlight or a reflector may be used for the illumination system. In forming the liquid crystal display device, a suitable part such as a diffusion plate, an anti-glare layer, an antireflection film, a protective plate, a prism array, a lens array sheet, a light diffusion plate, a backlight, Or more.

As the member C, a touch panel can be used. The touch panel C is a capacitive touch panel, and includes a transparent substrate, a pressure-sensitive adhesive layer 2, and a transparent conductive film in this order. The transparent conductive film can be laminated in two or more layers. The transparent gas may have a sensor layer. Further, the transparent substrate is a cover glass, a plastic cover or the like, which can be applied to an image display device (liquid crystal display device) alone. Alternatively, the transparent conductive film on the opposite side of the transparent substrate of the touch panel C may be provided with a hard coating film.

Examples of the transparent substrate include a glass plate and a transparent acrylic plate (PMMA plate). The transparent gas is a so-called cover glass and can be used as a decorative panel. As the transparent conductive film, a transparent conductive film is preferably formed on a glass plate or a transparent plastic film (particularly, a PET film). Examples of the transparent conductive film include a thin film containing a metal, a metal oxide, or a mixture thereof, and examples thereof include thin films of ITO (indium tin oxide), ZnO, SnO, and CTO (cadmium oxide tin oxide). The thickness of the transparent conductive film is not particularly limited, but is about 10 to 200 nm. As the transparent conductive film, an ITO film in which an ITO film is formed on a PET film is a representative example. The transparent conductive film can be formed through an undercoat layer. In addition, a plurality of undercoat layers can be formed. An oligomer migration prevention layer can be formed between the transparent plastic film substrate and the pressure-sensitive adhesive layer. It is preferable that the hard coating film is subjected to a hard coating treatment on a transparent plastic film such as a PET film.

The double-sided pressure-sensitive adhesive layer-attached polarizing film 10 of the present invention can be applied to, for example, a single-sided pressure-sensitive adhesive layer B-polarized polarizing film 12 having a polarizing film 1 and a pressure-sensitive adhesive layer B and having a separator SB in the pressure- Side adhesive layer A (11) having a pressure-sensitive adhesive layer A on the separator SA ₁ is laminated on the opposite polarizing film (1) on the side where the pressure-sensitive adhesive layer B is formed in the single-sided pressure-sensitive adhesive layer B- , So that the pressure-sensitive adhesive layer A of the one-side separator-attached pressure-sensitive adhesive layer A (11) is disposed. As shown in Fig. 6, the above-mentioned production method is preferably carried out by the step (1) of joining with roll-to-roll. 6, a step (1) is performed in which the single-sided pressure-sensitive adhesive layer B polarized film 12 conveyed from the delivery roll and the single-sided separator-attached pressure-sensitive adhesive layer A 11 are bonded between the pair of bonding rolls R1 and R2, A double-sided pressure-sensitive adhesive layer-containing polarizing film 10 is obtained by a winding roll.

Further, the one-sided separator-bonded pressure-sensitive adhesive layer A (11) can be obtained from the pressure-sensitive adhesive layer A (14) with a separator SA ₁ on one side of the pressure-sensitive adhesive layer A and the separator SA ₂ on the other side thereof. A pressure-sensitive adhesive layer over both sides of the separator 14 may be expressed by the separator SA ₁ / adhesive layer A / separator configuration of the SA ₂ as shown in Fig. 6, a step (a) of peeling the separator SA ₂ is carried out by the peeling roll R 3 in the pressure-sensitive adhesive layer A (14) with a separator attached to the both sides conveyed from the delivery roll, And the pressure-sensitive adhesive layer A (11) is supplied.

When using the separator on both sides over the pressure-sensitive adhesive layer A (14), the separator, the peeling strength of a ₁ SA _1, SA ₂ of the separator peeling force a _2, the peel force of the separator SB b is a _1> a ₂ ≥b Is preferable from the viewpoint of the process sequence of the product and the sequence of the bonding process to the liquid crystal panel, the organic EL panel, and the like. Further, the point of the separator SA peeling strength of ₁ a _1, the separators ₂ SA peeling strength of a _2, b release force of the separator is a SB _1> to improve workability which satisfies the relationship of 1.5a ₂ ≥1.5b .

Peel force of the separator SA ₁ a _1, peeling strength of the separator SB b are as defined above. Peel force of the separator SA _{2 2} a 0.01 to 5N / 50mm is not preferable, and further preferably in a 0.05 to 2N / 50mm, preferably in the addition of 0.05 to 1N / 50mm. The separator SA ₁ peel force a ₁ and the separators ₂ SA peel force a car ₂ is from 0.01 to 1N / 50mm preferred from the workability of the bonding process of the polarizing plate of the, further, that the range of 0.03 to 0.5N / 50mm desirable.

In the step (1) of joining the double-sided pressure-sensitive adhesive layer-containing polarizing film (10) of the present invention with the roll-to-roll bonding, the tension T1 of the separator- (T1 / T2) of the tensile force T2 of the first to twelfth rollers is controlled to 0.8 or more. In Fig. 6, the tension T1 and the tension T2 can be controlled by the rolls R11 and R12.

By controlling the tension ratio (T1 / T2) in the above range, the curl amount can be adjusted. The tension ratio (T1 / T2) is preferably 0.9 or more, more preferably 1 or more, and further preferably 3 or more. On the other hand, if the tension ratio (T1 / T2) is too large, the curl amount becomes too large and the joining accuracy in the joining step to the panel decreases. Therefore, the tension ratio T1 / T2 is preferably 10 or less, more preferably 6 or less, Or less.

The tensile stress T1 is preferably 8 to 500 N / m, more preferably 50 to 300 N / m, and further preferably 100 to 200 N / m.

The tensile strength T2 is preferably 10 to 400 N / m, more preferably 20 to 200 N / m, further preferably 40 to 100 N / m.

In the present invention, after preparing a polarizing film (10) over the double-sided pressure-sensitive adhesive layer was then peeled off the separator SA ₁ from the adhesive layer A of the double-sided pressure-sensitive adhesive layer polarizing film (10) over the obtained separator SA ₁ peeling Sensitive adhesive layer can be produced by bonding the curl adjusting separator SA ₁ 'to the pressure-sensitive adhesive layer A of the double-sided pressure-sensitive adhesive layer-attached polarizing film 13. By using the curl adjusting separator SA ₁ 'instead of the separator SA ₁ , the curl amount of the polarizing film 10' with double-sided pressure-sensitive adhesive layer can be adjusted. As shown in Fig. 7, the above-mentioned production method is preferably carried out by a step (2) of joining with roll-to-roll.

In Figure 7, the polarizing film 10, over both sides of the pressure-sensitive adhesive layer to be conveyed from the delivery rolls has been carried out the step (b) of peeling off the separator SA ₁ by the peeling roll R6. Subsequently, the step (2) of bonding the double-sided pressure-sensitive adhesive layer-carrying polarizing film 13 and the curling adjusting separator SA ₁ 'between the pair of bonding rolls R 4 and R 5 is carried out, The film 10 'is obtained.

In the above-described curl-adjustment separator SA ₁ relationship between "a peeling force of _1, the separator peeling force of SA ₁ and a ₁ in the same range it is desirable, and further the peeling strength of the separator SB b, a ₁ '> of 1.5b It is preferable from the viewpoint of curl adjustment to satisfy the relationship.

Further, the polarizing film (10 ') over both sides of the pressure-sensitive adhesive layer of the present invention, the roll-to-roll, according to the bonding step (2), the curl adjusting separator SA _1' tension T3 and the separator SA-sided pressure-sensitive adhesive ₁ is peeled off the It is preferable to control the ratio (T3 / T4) of the layered polarizing film 13 to the tension T4 to 0.8 or more. In Fig. 7, the tension T3 and the tension T4 can be controlled by the rolls R13 and R14.

By controlling the tension ratio T3 / T4 in the above range, the curl amount can be adjusted. The tension ratio (T3 / T4) is preferably 0.9 or more, more preferably 1 or more, and further preferably 3 or more. On the other hand, if the tension ratio (T3 / T4) is too large, the curl amount becomes too large and the joining accuracy in the joining step to the panel is lowered. Therefore, the tension ratio T3 / T4 is preferably 10 or less, Or less.

The tensile strength T3 is preferably 8 to 500 N / m, more preferably 50 to 300 N / m, more preferably 100 to 200 N / m.

The tensile force T4 is preferably 10 to 400 N / m, more preferably 20 to 200 N / m, further preferably 40 to 100 N / m.

Further, the magnitude of the tension can be adjusted by the torque of the roll and the like, and the method of giving the tension is not particularly limited. However, when a film or the like is fed by a roll, tension can be applied in the feeding direction. In addition, the tension can be measured by, for example, a load cell type tension pickup roll which can be measured by a load applied to a transport roll. The tension is measured by the method described in the embodiment.

The obtained method of producing a polarizing film with double-sided pressure-sensitive adhesive layer may then include a step (c) of cutting to an arbitrary size and a step (d) of cutting the end of the polarized film with double-sided pressure-sensitive adhesive layer. The cutting step (d) may include a polishing step.

<Material of Pressure-Sensitive Adhesive Layer>

As the material for forming the pressure-sensitive adhesive layer A and the pressure-sensitive adhesive layer B of the present invention, those containing various base polymers can be used. There is no particular limitation on the kind of the base polymer, and examples thereof include a rubber polymer, a (meth) acrylic polymer, a silicone polymer, a urethane polymer, a vinyl alkyl ether polymer, a polyvinyl alcohol polymer, a polyvinyl pyrrolidone polymer, Acrylamide-based polymers, cellulose-based polymers, and the like.

Of these base polymers, those having excellent optical transparency, exhibiting appropriate wettability, cohesiveness and adhesiveness with adhesiveness, and having excellent weather resistance and heat resistance are preferably used. The (meth) acrylic polymer is preferably used as this feature. Hereinafter, an acrylic pressure-sensitive adhesive using a (meth) acryl-based polymer containing alkyl (meth) acrylate as a monomer unit as the base polymer for the pressure-sensitive adhesive layer A and the pressure-sensitive adhesive layer B will be described.

The (meth) acrylic polymer is obtained by polymerizing a monomer component containing an alkyl (meth) acrylate having an alkyl group having 4 to 24 carbon atoms at the terminal of an ester group. The alkyl (meth) acrylate refers to alkyl acrylate and / or alkyl methacrylate, and (meth) of the present invention has the same meaning.

As the alkyl (meth) acrylate, those having a linear or branched alkyl group having 4 to 24 carbon atoms can be exemplified. The alkyl (meth) acrylate may be used singly or in combination of two or more.

Examples of the alkyl (meth) acrylate include alkyl (meth) acrylates having a branch having 4 to 9 carbon atoms. The alkyl (meth) acrylate is preferable in view of easy balance of adhesive properties. Examples of the alkyl (meth) acrylate include n-butyl (meth) acrylate, isobutyl (meth) acrylate, n-pentyl (meth) acrylate, (Meth) acrylate, isopentyl (meth) acrylate, isopentyl (meth) acrylate, isohexyl (meth) acrylate, isoheptyl Methacrylate, and the like. In addition, the (meth) acrylic polymer relating to the pressure-sensitive adhesive layer A preferably contains 2-ethylhexyl acrylate as the monomer unit in view of the stepwise absorbency by controlling the storage elastic modulus. In the case where the pressure-sensitive adhesive layer A is a multiple pressure-sensitive adhesive layer having at least the first pressure-sensitive adhesive layer (a) and the second pressure-sensitive adhesive layer (b), the (meth) acryl- As the unit, it is preferable that 2-ethylhexyl acrylate is contained in the largest amount. On the other hand, the (meth) acryl-based polymer relating to the pressure-sensitive adhesive layer B preferably contains the most butyl acrylate as a monomer unit from the viewpoints of processability, storage stability and durability by controlling the storage elastic modulus.

In the present invention, the alkyl (meth) acrylate having the alkyl group having 4 to 24 carbon atoms at the ester terminal is not less than 40% by weight based on the total amount of the monofunctional monomer component forming the (meth) acrylic polymer, preferably 50 By weight or more, more preferably 60% by weight or more. It is preferable to use at least 40% by weight in view of easy balance of adhesive properties.

The monomer component forming the (meth) acrylic polymer of the present invention may contain, as the monofunctional monomer component, a copolymerizable monomer other than the alkyl (meth) acrylate. The copolymerizable monomer may be used as a remaining part of the alkyl (meth) acrylate in the monomer component.

As the copolymerizable monomer, for example, a cyclic nitrogen-containing monomer may be contained. As the cyclic nitrogen-containing monomer, those having a polymerizable functional group having an unsaturated double bond such as a (meth) acryloyl group or a vinyl group and having a cyclic nitrogen structure can be used without particular limitation. The cyclic nitrogen structure preferably has a nitrogen atom in the cyclic structure. Examples of the cyclic nitrogen-containing monomer include lactam-based vinyl monomers such as N-vinyl pyrrolidone, N-vinyl-epsilon -caprolactam and methyl vinyl pyrrolidone; Vinyl monomers having a nitrogen-containing heterocyclic ring such as vinylpyridine, vinylpiperidone, vinylpyrimidine, vinylpiperazine, vinylpyrazine, vinylpyrrole, vinylimidazole, vinyloxazole and vinylmorpholine. Further, (meth) acrylic monomers containing a heterocyclic ring such as morpholine ring, piperidine ring, pyrrolidine ring and piperazine ring can be mentioned. Specific examples thereof include N-acryloylmorpholine, N-acryloylpiperidine, N-methacryloylpiperidine, N-acryloylpyrrolidine and the like. Of the cyclic nitrogen-containing monomers, lactam-based vinyl monomers are preferred from the viewpoint of the dielectric constant and cohesiveness.

In the present invention, the content of the cyclic nitrogen-containing monomer is preferably 45% by weight or less, more preferably 0.5 to 40% by weight, and still more preferably 0.5 to 30% by weight, based on the total monomer components forming the (meth) . Use of the cyclic nitrogen-containing monomer within the above range is preferable from the viewpoints of control of the surface resistance value, compatibility with an ionic compound in the case of using an ionic compound, and durability of an antistatic function.

The monomer component for forming the (meth) acrylic polymer of the present invention may include, for example, a monomers having a hydroxyl group-containing monomer, a carboxyl group-containing monomer and a cyclic ether group as monofunctional monomer components.

As the hydroxyl group-containing monomer, those having a polymerizable functional group having an unsaturated double bond such as a (meth) acryloyl group or a vinyl group and having a hydroxyl group can be used without particular limitation. Examples of the hydroxyl group-containing monomer include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 3-hydroxypropyl (Meth) acrylate, 4-hydroxybutyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, 8- Hydroxyalkyl (meth) acrylates such as hydroxy lauryl (meth) acrylate and the like; (4-hydroxymethylcyclohexyl) methyl (meth) acrylate, and other hydroxyalkylcycloalkane (meth) acrylates. Other examples include hydroxyethyl (meth) acrylamide, allyl alcohol, 2-hydroxyethyl vinyl ether, 4-hydroxybutyl vinyl ether, and diethylene glycol monovinyl ether. These may be used alone or in combination. Of these, hydroxyalkyl (meth) acrylates are suitable.

As the carboxyl group-containing monomer, those having a polymerizable functional group having an unsaturated double bond such as a (meth) acryloyl group or a vinyl group and having a carboxyl group can be used without particular limitation. Examples of the carboxyl group-containing monomer include (meth) acrylic acid, carboxyethyl (meth) acrylate, carboxypentyl (meth) acrylate, itaconic acid, maleic acid, fumaric acid, crotonic acid, isocrotonic acid, May be used alone or in combination. Itaconic acid and maleic acid may be used as anhydrides thereof. Among these, acrylic acid and methacrylic acid are preferable, and acrylic acid is particularly preferable. In addition, a carboxyl group-containing monomer may optionally be used as the monomer component used in the production of the (meth) acrylic polymer of the present invention, and on the other hand, a carboxyl group-containing monomer may not be used. A pressure-sensitive adhesive containing a (meth) acryl-based polymer obtained from a monomer component containing no carboxyl group-containing monomer can form a pressure-sensitive adhesive layer in which metal corrosion caused by a carboxyl group is reduced.

As the monomer having a cyclic ether group, a monomer having a polymerizable functional group having an unsaturated double bond such as a (meth) acryloyl group or a vinyl group and having a cyclic ether group such as an epoxy group or an oxetane group can be used without particular limitation. Examples of the epoxy group-containing monomer include glycidyl (meth) acrylate, 3,4-epoxycyclohexylmethyl (meth) acrylate and 4-hydroxybutyl (meth) acrylate glycidyl ether . Examples of the oxetane group-containing monomer include 3-oxetanylmethyl (meth) acrylate, 3-methyloxetanylmethyl (meth) acrylate, 3-ethyloxetanylmethyl (meth) Butyloxetanylmethyl (meth) acrylate, 3-hexyloxetanylmethyl (meth) acrylate, and the like. These may be used alone or in combination.

In the present invention, the monomer having a hydroxyl group-containing monomer, a carboxyl group-containing monomer and a cyclic ether group is preferably 30% by weight or less, more preferably 27% by weight or less based on the total amount of the monofunctional monomer component forming the (meth) , Further preferably not more than 25% by weight.

The monomer component forming the (meth) acrylic polymer of the present invention may include, for example, CH ₂ ═C (R ¹ ) COOR ² (wherein R ¹ is hydrogen or a methyl group, R ² is a A substituted or unsubstituted alkyl group or a substituted alkyl group, or a cyclic cycloalkyl group).

Here, the unsubstituted or substituted alkyl group having 1 to 3 carbon atoms as R ² represents a straight-chain or branched-chain alkyl group. In the case of the substituted alkyl group, the substituent is preferably an aryl group having 3 to 8 carbon atoms or an aryloxy group having 3 to 8 carbon atoms. The aryl group is not limited, but a phenyl group is preferable.

Examples of the monomer represented by CH ₂ ═C (R ¹ ) COOR ² include methyl (meth) acrylate, ethyl (meth) acrylate, phenoxyethyl (meth) acrylate, benzyl (meth) acrylate, cyclohexyl (Meth) acrylate, 3,3,5-trimethylcyclohexyl (meth) acrylate, isobornyl (meth) acrylate and the like. These may be used alone or in combination.

In the present invention, the (meth) acrylate represented by CH ₂ C (R ¹ ) COOR ² may be used in an amount of 45% by weight or less based on the total amount of the monofunctional monomer component forming the (meth) By weight or less is preferable. More preferably 30% by weight or less.

Other copolymerizable monomers include vinyl acetate, vinyl propionate, styrene,? -Methyl styrene; Glycol acrylate monomers such as (meth) acrylic acid polyethylene glycol, (meth) acrylic acid polypropylene glycol, (meth) acrylic acid methoxyethylene glycol and (meth) acrylic acid methoxypolypropylene glycol; Acrylate monomers such as (meth) acrylate tetrahydrofurfuryl, fluorine (meth) acrylate, silicone (meth) acrylate and 2-methoxyethyl acrylate; Amide group-containing monomers, amino group-containing monomers, imide group-containing monomers, N-acryloylmorpholine, vinyl ether monomers and the like. As the copolymerizable monomer, a monomer having a cyclic structure such as terpene (meth) acrylate or dicyclopentanyl (meth) acrylate can be used.

Silane-based monomers containing silicon atoms, and the like. Examples of the silane-based monomer include 3-acryloxypropyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, 4-vinylbutyltrimethoxysilane, 4-vinylbutyltriethoxysilane, 8- Vinyl octyl trimethoxysilane, 8-vinyl octyl triethoxysilane, 10-methacryloyloxydecyl trimethoxysilane, 10-acryloyloxydecyl trimethoxysilane, 10-methacryloyloxydecyl tri Ethoxysilane, 10-acryloyloxydecyltriethoxysilane, and the like.

The copolymerizable monomer can be appropriately selected at the time of forming the pressure-sensitive adhesive layer A and the pressure-sensitive adhesive layer B at the time of production of the (meth) acrylic polymer as the base polymer. When the first pressure-sensitive adhesive layer (a) and the pressure-sensitive adhesive layer B in the pressure-sensitive adhesive layer A are formed by an acrylic pressure-sensitive adhesive, as the copolymerizable monomer, at least one of them is preferable from the viewpoints of cohesion, adhesive strength, transparency, and durability , It is preferable that at least one of (meth) acrylic acid and nitrogen-containing monomer is contained as the monomer unit.

The monomer component forming the (meth) acrylic polymer of the present invention may contain, in addition to the monofunctional monomers exemplified above, a multifunctional monomer as necessary in order to adjust the cohesive force of the pressure-sensitive adhesive.

The polyfunctional monomer is a monomer having at least two polymerizable functional groups having an unsaturated double bond such as a (meth) acryloyl group or a vinyl group, and examples thereof include (poly) ethylene glycol di (meth) acrylate, Propylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, pentaerythritol di (meth) acrylate, pentaerythritol tri (meth) acrylate, propoxylated pentaerythritol triacrylate, di (Meth) acrylate, 1,6-hexanediol di (meth) acrylate, 1,12-dodecanediol di (meth) acrylate, Ester compounds of polyhydric alcohols such as trimethylolpropane tri (meth) acrylate and tetramethylol methane tri (meth) acrylate with (meth) acrylic acid; (Meth) acrylate, vinyl (meth) acrylate, divinylbenzene, epoxy acrylate, polyester acrylate, urethane acrylate, butanediol di (meth) acrylate, hexanediol di . Among them, trimethylolpropane tri (meth) acrylate, hexanediol di (meth) acrylate and dipentaerythritol hexa (meth) acrylate can be suitably used. The polyfunctional monomers may be used singly or in combination of two or more.

The amount of the polyfunctional monomer to be used is different depending on the molecular weight or the number of functional groups and is preferably 3 parts by weight or less, more preferably 2 parts by weight or less, and 1 part by weight or less based on 100 parts by weight of the total amount of monofunctional monomers Is more preferable. The lower limit is not particularly limited, but is preferably 0 part by weight or more, more preferably 0.001 part by weight or more. When the usage amount of the polyfunctional monomer is within the above range, the adhesive force can be improved.

Such a (meth) acrylic polymer can be appropriately selected from known production methods such as various radical polymerization such as solution polymerization, radiation polymerization such as ultraviolet polymerization, bulk polymerization, emulsion polymerization and the like. The (meth) acrylic polymer to be obtained may be any of a random copolymer, a block copolymer and a graft copolymer.

The polymerization initiator, chain transfer agent and emulsifier used in the radical polymerization are not particularly limited and can be appropriately selected and used. The weight average molecular weight of the (meth) acryl-based polymer can be controlled by the amount of the polymerization initiator, the amount of the chain transfer agent, and the reaction conditions, and the amount of the (meth) acrylic polymer is appropriately adjusted depending on the kind thereof.

For example, in solution polymerization, ethyl acetate, toluene and the like are used as the polymerization solvent, for example. As concrete solution polymerization, the reaction is carried out under a reaction condition of usually about 50 to 70 DEG C for about 5 to 30 hours by adding a polymerization initiator under an inert gas stream such as nitrogen.

Examples of the thermal polymerization initiator used for solution polymerization and the like include 2,2'-azobisisobutyronitrile, 2,2'-azobis-2-methylbutyronitrile, 2,2'-azobis (2 (2-amidinopropane) dihydrochloride, 2,2'-azobisisobalenoic acid, 2,2'-azobis (2-amidinopropane) dihydrochloride, Azobis [2- (5-methyl-2-imidazolin-2-yl) propane] dihydrochloride, 2,2'- Azobis (N, N'-dimethyleneisobutylamidine), 2,2'-azobis [N- (2-carboxyethyl) -2-methylpropionamidine] hydrate (VA- 057 (2-ethylhexyl) peroxydicarbonate, di (4-t-butylcyclohexyl) peroxydicarbonate, di-tert-butyl peroxydicarbonate, butyl peroxydicarbonate, t-butyl peroxyneodecanoate , t-hexylperoxy pivalate, t-butyl peroxypivalate, dilauryl peroxide, di-n-octanoyl peroxide, 1,1,3,3-tetramethylbutylperoxy-2-ethyl Butyl peroxy isobutyrate, 1,1-di (t-hexyl peroxy) cyclohexane, t-butyl hydroperoxide, hydrogen peroxide , A combination of a persulfate and sodium hydrogen sulfite, a combination of a peroxide and sodium ascorbate, and a redox initiator in combination with a reducing agent. However, the present invention is not limited thereto.

The polymerization initiator may be used singly or in admixture of two or more. The content of the polymerization initiator is preferably about 0.005 to 1 part by weight, more preferably about 0.02 to 0.5 part by weight, based on 100 parts by weight of the monomer More preferable.

In order to produce the (meth) acrylic polymer having the weight average molecular weight by using, for example, 2,2'-azobisisobutyronitrile as the polymerization initiator, the amount of the polymerization initiator used is preferably 100 parts by weight , Preferably about 0.06 to 0.2 part by weight, more preferably about 0.08 to 0.175 part by weight.

Examples of the chain transfer agent include lauryl mercaptan, glycidyl mercaptan, mercaptoacetic acid, 2-mercaptoethanol, thioglycolic acid, 2-ethylhexyl thioglycolate, 2,3-dimercapto-1-propanol And the like. The chain transfer agent may be used singly or in admixture of two or more, but the total content is about 0.1 part by weight or less based on 100 parts by weight of the total amount of the monomer components.

Examples of the emulsifier used in the case of emulsion polymerization include sodium lauryl sulfate, ammonium lauryl sulfate, sodium dodecylbenzenesulfonate, ammonium polyoxyethylene alkylether sulfate and sodium polyoxyethylene alkylphenylether sulfate. Nonionic emulsifiers such as anionic emulsifiers, polyoxyethylene alkyl ethers, polyoxyethylene alkyl phenyl ethers, polyoxyethylene fatty acid esters and polyoxyethylene-polyoxypropylene block polymers. These emulsifiers may be used alone or in combination of two or more.

Examples of the emulsifier to which a radically polymerizable functional group such as a propenyl group or an allyl ether group is introduced as a reactive emulsifier include Aquarone HS-10, HS-20, KH-10, BC-05, BC -10, and BC-20 (all manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.) and Adekariasso SE10N (manufactured by ADEKA). Since the reactive emulsifier is introduced into the polymer chain after the polymerization, the water resistance is preferably improved. The amount of the emulsifier to be used is more preferably 0.3 to 5 parts by weight based on 100 parts by weight of the total amount of the monomer components, more preferably 0.5 to 1 part by weight in terms of polymerization stability and mechanical stability.

When the (meth) acrylic polymer is produced by active energy ray polymerization, the monomer component can be produced by polymerizing by irradiating active energy ray such as electron beam or ultraviolet ray. When the active energy ray polymerization is carried out by electron beam, it is not particularly necessary to include a photopolymerization initiator in the monomer component. However, when the active energy ray polymerization is carried out by ultraviolet polymerization, the advantage of being able to shorten the polymerization time , The photopolymerization initiator may be contained in the monomer component. The photopolymerization initiator may be used singly or in combination of two or more. The monomer component may be a syrup obtained by polymerizing a part of the monomer in advance in the irradiation of radiation.

The photopolymerization initiator is not particularly limited and is not particularly limited as long as it initiates photopolymerization, and a commonly used photopolymerization initiator can be used. Examples of the initiator include benzoin ether photopolymerization initiator, acetophenone photopolymerization initiator,? -Ketol photopolymerization initiator, aromatic sulfonyl chloride photopolymerization initiator, photoactive oxime photopolymerization initiator, benzoin photopolymerization initiator, benzyl photopolymerization initiator, A phenanone-based photopolymerization initiator, a ketal-based photopolymerization initiator, a thioxanthone-based photopolymerization initiator, and an acylphosphine oxide-based photopolymerization initiator.

Specific examples of the benzoin ether photopolymerization initiator include benzoin methyl ether, benzoin ethyl ether, benzoin propyl ether, benzoin isopropyl ether, benzoin isobutyl ether, 2,2-dimethoxy-1 , 2-diphenylethan-1-one (trade name: Irgacure 651, manufactured by BASF), and anisoin methyl ether. Examples of the acetophenone-based photopolymerization initiator include 1-hydroxycyclohexyl phenyl ketone (trade name: Irgacure 184, BASF), 4-phenoxydichloroacetophenone, 4-t-butyl-dichloroacetophenone 2-methyl-1-propan-1-one [Product name: Irgacure 2959, BASF], 2 - [2 - hydroxyethoxy] Methyl-1-phenyl-propan-1-one (trade name: DARACURE 1173, BASF), methoxyacetophenone and the like. Examples of the? -ketol-based photopolymerization initiator include 2-methyl-2-hydroxypropiophenone, 1- [4- (2-hydroxyethyl) -phenyl] -2-hydroxy- - on. The aromatic sulfonyl chloride-based photopolymerization initiator includes, for example, 2-naphthalenesulfonyl chloride. Examples of the photoactive oxime-based photopolymerization initiator include 1-phenyl-1,2-propanedione-2- (O-ethoxycarbonyl) -oxime and the like.

The benzoin-based photopolymerization initiator includes, for example, benzoin and the like. The benzyl-based photopolymerization initiator includes, for example, benzyl and the like. The benzophenone-based photopolymerization initiator includes, for example, benzophenone, benzoylbenzoic acid, 3,3'-dimethyl-4-methoxybenzophenone, polyvinylbenzophenone,? -Hydroxycyclohexylphenylketone and the like. The ketal group photopolymerization initiator includes, for example, benzyl dimethyl ketal and the like. Examples of the thioxanthene photopolymerization initiator include thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, 2,4-dimethylthioxanthone, isopropylthioxanthone, 2,4- Hexanedioxanthone, octanedioxanthone, octanedioxanthone, isocyanthene, 2,4-diethylthioxanthone, isopropylthioxanthone, 2,4-diisopropylthioxanthone, dodecylthioxanthone and the like.

Examples of the acylphosphine oxide photopolymerization initiator include bis (2,6-dimethoxybenzoyl) phenylphosphine oxide, bis (2,6-dimethoxybenzoyl) (2,4,4-trimethylpentyl) Phosphine oxide, bis (2,6-dimethoxybenzoyl) -n-butylphosphine oxide, bis (2,6-dimethoxybenzoyl) - (2-methylpropan- Bis (2,6-dimethoxybenzoyl) - (1-methylpropan-1-yl) phosphine oxide, bis (2,6- dimethoxybenzoyl) -t-butylphosphine oxide, bis (2-methoxybenzoyl) octylphosphine oxide, bis (2-methoxybenzoyl) cyclohexylphosphine oxide, bis (2,6-dimethoxybenzoyl) , Bis (2,6-diethoxybenzoyl) (2-methylpropan-1-yl) phosphine oxide, bis (2-methoxybenzoyl) (2,6-diethoxybenzoyl) (1-methylpropan-1-yl) phosphine oxide, bis (2,6-dibutoxybenzoyl) (2,4-dimethoxybenzoyl) (2-methylpropan-1-yl) phosphine oxide, bis (2,4,6-trimethylbenzoyl) Bis (2,6-dimethoxybenzoyl) benzylphosphine oxide, bis (2,6-dimethoxybenzoyl) -2-phenylpropylphosphine oxide, bis (2,6- dimethoxybenzoyl) (2,6-dimethoxybenzoyl) -2-phenylpropylphosphine oxide, bis (2,6-dimethoxybenzoyl) benzylphosphine oxide, bis 2-phenylethylphosphine oxide, 2,6-dimethoxybenzoylbenzylbutylphosphine oxide, 2,6-dimethoxybenzoylbenzyloctylphosphine oxide, bis (2,4,6-dimethoxybenzoyl) Bis (2,4,6-trimethylbenzoyl) -2,5-diisopropylphenylphosphine oxide, bis (2,4,6-trimethylbenzoyl) 4-methylphenylphosphine oxide, bis (2,4,6-trimethylbenzoyl) -2,5-diethylphenylphosphine oxide, bis (2,4,6-trimethylbenzoyl) -2,3,5,6-tetramethylphenylphosphine oxide, bis (2,4,6-trimethylbenzoyl) -2,4-di-n-butoxyphenylphosphine (2,4,6-trimethylbenzoyldiphenylphosphine oxide), bis (2,6-dimethoxybenzoyl) -2,4,4-trimethylpentylphosphine oxide, bis (Trimethylbenzoyl) isobutylphosphine oxide, 2,6-dimethoxybenzoyl-2,4,6-trimethylbenzoyln-butylphosphine oxide, bis (2,4,6-trimethylbenzoyl) phenylphosphine Bis [bis (2,4,6-trimethylbenzoyl) phosphineoxide] decane, bis (2,4,6-trimethylbenzoyl) -2,4-dibutoxyphenylphosphine oxide, Tri (2-methylbenzoyl) phosphine oxide, and the like.

The amount of the photopolymerization initiator to be used is not particularly limited, but is, for example, from 0.01 to 5 parts by weight, preferably from 0.05 to 3 parts by weight, more preferably from 0.05 to 1.5 parts by weight, relative to 100 parts by weight of the monomer component 0.1 to 1 part by weight.

If the amount of the photopolymerization initiator used is less than 0.01 part by weight, the polymerization reaction may be insufficient. If the photopolymerization initiator is used in an amount exceeding 5 parts by weight, the photopolymerization initiator absorbs ultraviolet rays, so that ultraviolet rays may not reach the inside of the pressure sensitive adhesive layer. In this case, the polymerization rate is lowered or the molecular weight of the resulting polymer is reduced. As a result, the cohesive force of the formed pressure-sensitive adhesive layer is lowered, and when the pressure-sensitive adhesive layer is peeled from the film, a part of the pressure-sensitive adhesive layer remains on the film, and the film can not be reused. The photopolymerization initiator may be used alone or in combination of two or more.

The weight average molecular weight of the (meth) acrylic polymer of the present invention is preferably 400,000 to 2,500,000, and more preferably 600,000 to 2,200,000. By making the weight average molecular weight greater than 400,000, the durability of the pressure-sensitive adhesive layer can be satisfied, or the cohesive force of the pressure-sensitive adhesive layer can be reduced, and the occurrence of adhesive residue can be suppressed. On the other hand, if the weight average molecular weight exceeds 2.5 million, the bonding property and the adhesive strength tend to be lowered. Further, when the pressure-sensitive adhesive is a solution type, the viscosity becomes too high, which may make coating application difficult. The weight average molecular weight refers to a value measured by GPC (gel permeation chromatography) and calculated by polystyrene conversion. Further, it is difficult to measure the molecular weight of the (meth) acrylic polymer obtained by the radiation polymerization.

&Lt; Measurement of weight average molecular weight >

The weight average molecular weight of the resulting (meth) acrylic polymer was measured by GPC (gel permeation chromatography). A sample was prepared by dissolving a sample in tetrahydrofuran to prepare a 0.1 wt% solution. The solution was allowed to stand overnight, and then filtered through a 0.45 μm membrane filter.

Analytical Apparatus: manufactured by Toso Co., Ltd., HLC-8120GPC

Column: (meth) acrylic polymer: GM7000H _XL + GMH _XL + GMH _XL

· Aromatic polymer: G3000HXL + 2000HXL + G1000HXL

Column size; Each 7.8mmφ × 30cm system 90cm

Eluent: tetrahydrofuran (concentration 0.1% by weight)

· Flow rate: 0.8 ml / min

· Inlet pressure: 1.6 MPa

Detector: Differential refractometer (RI)

Column temperature: 40 ° C

· Injection volume: 100 μl

Eluent: tetrahydrofuran

· Detector: Differential refractometer

· Standard sample: Polystyrene

The pressure-sensitive adhesive for forming the pressure-sensitive adhesive layer A and the pressure-sensitive adhesive layer B of the present invention may contain a crosslinking agent. Examples of the crosslinking agent include crosslinking agents such as an isocyanate crosslinking agent, an epoxy crosslinking agent, a silicone crosslinking agent, an oxazoline crosslinking agent, an aziridine crosslinking agent, a silane crosslinking agent, an alkyletherified melamine crosslinking agent, a metal chelating crosslinking agent and a peroxide. The crosslinking agent may be used alone or in combination of two or more. As the crosslinking agent, an isocyanate crosslinking agent and an epoxy crosslinking agent are preferably used.

The crosslinking agent may be used alone or in admixture of two or more. The content of the crosslinking agent may be in the range of 0.01 to 5 parts by weight based on 100 parts by weight of the (meth) acryl-based polymer . The content of the crosslinking agent is preferably 0.01 to 4 parts by weight, more preferably 0.02 to 3 parts by weight.

The isocyanate crosslinking agent refers to a compound having two or more isocyanate groups (containing an isocyanate regenerable functional group temporarily protected by an isocyanate group as a blocking agent or a quantification) in one molecule.

Examples of the isocyanate crosslinking agent include aromatic isocyanates such as tolylene diisocyanate and xylylene diisocyanate; alicyclic isocyanates such as isophorone diisocyanate; and aliphatic isocyanates such as hexamethylene diisocyanate.

More specifically, examples thereof include lower aliphatic polyisocyanates such as butylene diisocyanate and hexamethylene diisocyanate, alicyclic isocyanates such as cyclopentylene diisocyanate, cyclohexylene diisocyanate and isophorone diisocyanate, Aromatic diisocyanates such as 4-tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, xylylene diisocyanate and polymethylene polyphenyl isocyanate, trimethylolpropane / tolylene diisocyanate trimer adducts Trimethylolpropane / hexamethylene diisocyanate trimeric adduct (manufactured by Nippon Polyurethane Industry Co., Ltd., Coronate HL), hexamethylene diisocyanate isocyanurate (Nippon Polyurethane Co., Ltd., High school priest, product name Corona Trimethylol propane adduct of xylylene diisocyanate (trade name: D110N, manufactured by Mitsui Chemical Industry Co., Ltd.), trimethylol propane adduct of hexamethylene diisocyanate (trade name D160N, manufactured by Mitsui Chemical Industry Co., Ltd.); Polyether polyisocyanate, polyester polyisocyanate, adducts of these with various polyols, polyisocyanates multifunctionalized by isocyanurate bond, buret bond, allophanate bond and the like. Of these, it is preferable to use an aliphatic isocyanate because the reaction rate is fast.

The isocyanate crosslinking agent may be used alone or in admixture of two or more. The content of the isocyanate crosslinking agent may be 0.01 to 5 parts by weight, based on 100 parts by weight of the (meth) acrylic polymer, of the isocyanate crosslinking agent By weight, more preferably 0.01 to 4 parts by weight, further preferably 0.02 to 3 parts by weight. Cohesive force, prevention of peeling in the durability test, and the like.

In addition, in the aqueous dispersion of the modified (meth) acrylic polymer produced by emulsion polymerization, it is not necessary to use an isocyanate cross-linking agent, but if necessary, the blocked isocyanate cross-linking agent may be used since it is easily reacted with water.

The epoxy cross-linking agent refers to a polyfunctional epoxy compound having two or more epoxy groups in one molecule. Examples of the epoxy cross-linking agent include bisphenol A, epichlorohydrin type epoxy resin, N, N, N ', N'-tetraglycidyl-m-xylylenediamine, diglycidyl aniline, 1,3 (N, N-diglycidylaminomethyl) cyclohexane, 1,6-hexanediol diglycidyl ether, neopentyl glycol diglycidyl ether, ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether Polyglycerol diglycidyl ether, sorbitol polyglycidyl ether, glycerol polyglycidyl ether, pentaerythritol polyglycidyl ether, glycerin diglycidyl ether , Glycerin triglycidyl ether, polyglycerol polyglycidyl ether, sorbitan polyglycidyl ether, trimethylolpropane polyglycidyl ether, adipic acid diglycidyl ester, o-phthalic acid diglycidyl (2-hydroxyethyl) isocyanurate, resorcin diglycidyl ether, bisphenol-S-diglycidyl ether, an epoxy resin having two or more epoxy groups in the molecule . Examples of the epoxy cross-linking agent include commercially available products such as Mitsubishi Gas Chemical Co., Ltd., Tertor C, Tertrade X and the like.

The epoxy-based crosslinking agent may be used singly or in admixture of two or more. The content of the epoxy-based crosslinking agent may be 0.01 to 5 parts by weight per 100 parts by weight of the (meth) acrylic polymer, By weight, more preferably 0.01 to 4 parts by weight, further preferably 0.02 to 3 parts by weight. Cohesive force, prevention of peeling in the durability test, and the like.

The cross-linking agent for the peroxide is not particularly limited as far as it is capable of generating radically active species by heating to promote crosslinking of the base polymer of the pressure-sensitive adhesive. However, in view of workability and stability, a peroxide having a half- And it is more preferable to use a peroxide having a temperature of 90 to 140 ° C.

Examples of peroxides that can be used include di (2-ethylhexyl) peroxydicarbonate (1 minute half-life temperature: 90.6 占 폚), di (4-t-butylcyclohexyl) peroxydicarbonate Butyl peroxy dicarbonate (1 minute half-life temperature: 103.5 占 폚), t-hexylperoxy (92.5 占 폚), di-sec-butylperoxydicarbonate (Half-life temperature for one minute: 109.1 占 폚), t-butyl peroxypivalate (one minute half life temperature: 110.3 占 폚), dilauroyl peroxide Tetramethylbutylperoxy-2-ethylhexanoate (1 minute half-life temperature: 124.3 占 폚), di (4-methylbenzoyl) Butyl peroxyisobutyrate (1 minute half-life temperature: 136.1 占 폚), 1,1-di (t-butylperoxy) isobutyrate -Hexylperoxy) cyclohexane (1 minute half-life temperature: 149.2 DEG C). Among them, di (4-t-butylcyclohexyl) peroxydicarbonate (half-life half-hour temperature: 92.1 占 폚) and dilauroyl peroxide (half-life half- ) And dibenzoyl peroxide (one-minute half-life temperature: 130.0 ° C) are preferably used.

The half-life period of peroxide is an index indicating the rate of decomposition of peroxide, and refers to the time until the amount of residual peroxide becomes half. The decomposition temperature for obtaining a half-life at an arbitrary time and the half-life time at an arbitrary temperature are described in the manufacturer's catalog. For example, the &quot; Organic Peroxide Catalog Ninth Edition &quot; Month) &quot;.

The peroxide may be used singly or in admixture of two or more. The total content of the peroxide is 0.02 to 2 parts by weight per 100 parts by weight of the (meth) acrylic polymer, preferably 0.05 to 1 part by weight By weight. Is appropriately selected within this range due to the adjustment of workability, reworkability, crosslinking stability, peelability and the like.

The method for measuring the amount of decomposed peroxide remaining after the reaction treatment can be measured by, for example, HPLC (high performance liquid chromatography).

More specifically, for example, about 0.2 g of the pressure-sensitive adhesive after the reaction treatment is taken out, immersed in 10 ml of ethyl acetate, shaken out at 25 DEG C at 120 rpm for 3 hours in a shaker, and then allowed to stand at room temperature for 3 days. Subsequently, 10 ml of acetonitrile was added, and the mixture was shaken at 25 DEG C at 120 rpm for 30 minutes, filtered through a membrane filter (0.45 mu m), and about 10 mu l of the extract was injected into HPLC to analyze the amount of peroxide after the reaction .

As the crosslinking agent, an organic crosslinking agent or a polyfunctional metal chelate may be used in combination. A polyfunctional metal chelate is one in which a polyvalent metal is covalently bonded or coordinated with an organic compound. Examples of the polyvalent metal atom include Al, Cr, Zr, Co, Cu, Fe, Ni, V, Zn, In, Ca, Mg, Mn, Y, Ce, Sr, Ba, Mo, La, Sn and Ti . Examples of the atom in the covalent bond or coordinate bond organic compound 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 pressure-sensitive adhesive for forming the pressure-sensitive adhesive layer A and the pressure-sensitive adhesive layer B of the present invention may contain a multifunctional monomer as a crosslinking agent. The multifunctional monomer is a monomer having at least two polymerizable functional groups having an unsaturated double bond such as a (meth) acryloyl group or a vinyl group, and the same examples as those exemplified as the monomer components for forming the (meth) acryl-based polymer are exemplified .

The multifunctional monomer as the crosslinking agent may be used alone or in admixture of two or more. The content of the multifunctional monomer as a whole may be 0.001 (the multifunctional monomer) relative to 100 parts by weight of the (meth) acrylic polymer By weight to 5 parts by weight. The content of the crosslinking agent (multifunctional monomer) is preferably 0.005 to 3 parts by weight, more preferably 0.01 to 1 part by weight.

A photopolymerization initiator is added to the pressure-sensitive adhesive to which the crosslinking agent (multifunctional monomer) is blended. As the photopolymerization initiator, those similar to those used for producing the (meth) acrylic polymer can be exemplified. The amount of the photopolymerization initiator to be used is generally 0.01 to 5 parts by weight, preferably 0.05 to 3 parts by weight, more preferably 0.05 to 1.5 parts by weight, more preferably 0.1 to 5 parts by weight based on 100 parts by weight of the crosslinking agent (multifunctional monomer) 1 part by weight. The pressure-sensitive adhesive compounded with the crosslinking agent (multifunctional monomer) is cured by irradiation with active energy rays to form a pressure-sensitive adhesive layer (active energy ray-curable pressure-sensitive adhesive layer).

The multiple pressure-sensitive adhesive layer relating to the pressure-sensitive adhesive layer A is preferably an active energy ray-curable pressure-sensitive adhesive layer in which at least one pressure-sensitive adhesive layer is formed by irradiation of an active energy ray to form a predetermined thickness. In particular, it is preferable that the first pressure-sensitive adhesive layer (a) and / or the second pressure-sensitive adhesive layer (b) is an active energy radiation curable pressure-sensitive adhesive layer.

The pressure-sensitive adhesive for forming the pressure-sensitive adhesive layer A and the pressure-sensitive adhesive layer B of the present invention may contain a (meth) acrylic oligomer in order to improve the adhesive strength. The (meth) acrylic oligomer is preferably a polymer having a higher Tg and a smaller weight average molecular weight than the (meth) acrylic polymer of the present invention. Such a (meth) acrylic oligomer functions as a tackifier resin and has an advantage of increasing the adhesive strength without increasing the dielectric constant.

The (meth) acrylic oligomer preferably has a Tg of about 0 ° C to 300 ° C, preferably about 20 ° C to 300 ° C, more preferably about 40 ° C to 300 ° C. If the Tg is less than about 0 캜, the cohesive strength of the pressure-sensitive adhesive layer at room temperature or higher is lowered, and the holding property and the adhesiveness at high temperature are sometimes lowered. The Tg of the (meth) acrylic oligomer is the same as the Tg of the (meth) acrylic polymer, and is a theoretical value calculated based on the Fox equation.

The weight average molecular weight of the (meth) acrylic oligomer is from 1,000 to less than 30,000, preferably from 1,500 to less than 20,000, more preferably from 2,000 to less than 10,000. If the weight average molecular weight is 30,000 or more, the effect of improving the adhesive strength may not be sufficiently obtained. On the other hand, if it is less than 1000, since the molecular weight is low, the adhesive strength and the holding property may be lowered. In the present invention, the measurement of the weight average molecular weight of the (meth) acrylic oligomer can be determined by polystyrene conversion by the GPC method. Specifically, the measurement was carried out under the conditions of a flow rate of about 0.5 ml / min in a tetrahydrofuran solvent using two columns of TSKgelGMH-H (20) as a column on HPLC8020 manufactured by Tosoh Corporation.

Examples of the monomer constituting the (meth) acrylic oligomer include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, butyl (Meth) acrylate, isobutyl (meth) acrylate, isobutyl (meth) acrylate, s-butyl (meth) acrylate, (Meth) acrylate, heptyl (meth) acrylate, octyl (meth) acrylate, isooctyl (meth) acrylate, nonyl ) Alkyl (meth) acrylates such as acrylate, isodecyl (meth) acrylate, undecyl (meth) acrylate and dodecyl (meth) acrylate; Esters of (meth) acrylic acid with alicyclic alcohols such as cyclohexyl (meth) acrylate, isobornyl (meth) acrylate and dicyclopentanyl (meth) acrylate; Aryl (meth) acrylates such as phenyl (meth) acrylate and benzyl (meth) acrylate; And (meth) acrylates obtained from terpene compound derivative alcohols. These (meth) acrylates may be used alone or in combination of two or more.

Examples of the (meth) acrylic oligomer include alkyl (meth) acrylates having an alkyl group such as isobutyl (meth) acrylate or t-butyl (meth) acrylate having a branched structure; Esters of (meth) acrylic acid with alicyclic alcohols such as cyclohexyl (meth) acrylate, isobornyl (meth) acrylate and dicyclopentanyl (meth) acrylate; (Meth) acrylate having a cyclic structure such as phenyl (meth) acrylate or aryl (meth) acrylate such as benzyl (meth) acrylate as a monomer unit . By having such a bulky structure in the (meth) acrylic oligomer, the adhesiveness of the pressure-sensitive adhesive layer can be further improved. Particularly, in terms of a large volume, the effect of having a cyclic structure is high, and the effect of containing a plurality of rings is more effective. When ultraviolet rays are employed in the synthesis of the (meth) acrylic oligomer or in the production of the pressure-sensitive adhesive layer, it is preferable to have a saturated bond in view of the difficulty of causing polymerization inhibition. The alkyl (meth) Acrylate or an alicyclic alcohol can be suitably used as a monomer constituting the (meth) acrylic oligomer.

In this respect, examples of suitable (meth) acrylic oligomers include copolymers of cyclohexyl methacrylate (CHMA) and isobutyl methacrylate (IBMA), copolymers of cyclohexyl methacrylate (CHMA) and isobornyl methacrylate Copolymer of cyclohexyl methacrylate (CHMA) and acryloylmorpholine (ACMO), copolymer of cyclohexyl methacrylate (CHMA) and diethyl acrylamide (DEAA), copolymer of cyclohexyl methacrylate A copolymer of adamantyl acrylate (ADA) and methyl methacrylate (MMA), a copolymer of dicyclopentanyl methacrylate (DCPMA) and isobornyl methacrylate (IBXMA), a copolymer of dicyclopentanyl methacrylate (DCPMA) and methyl methacrylate (MMA), copolymers of dicyclopentanyl methacrylate (DCPMA), cyclohexyl methacrylate (CHMA), isobornyl methacrylate (IBXMA), isobornyl acrylate IBXA) , Dicyclopentanyl acrylate (DCPA), 1-adamantyl methacrylate (ADMA), and 1-adamantyl acrylate (ADA). In particular, an oligomer containing CHMA as a main component is preferable.

When the (meth) acrylic oligomer is used in the pressure-sensitive adhesive for forming the pressure-sensitive adhesive layer A and the pressure-sensitive adhesive layer B of the present invention, the content thereof is not particularly limited, but is preferably 70 parts by weight or less based on 100 parts by weight of the More preferably 1 to 70 parts by weight, still more preferably 2 to 50 parts by weight, still more preferably 3 to 40 parts by weight. When the amount of the (meth) acryl-based oligomer is more than 70 parts by weight, the elasticity is increased and the adhesiveness at low temperatures is deteriorated. Also, when 1 part by weight or more of the (meth) acryl-based oligomer is blended, it is effective from the viewpoint of the adhesive force improving effect.

The pressure-sensitive adhesive for forming the pressure-sensitive adhesive layer A and the pressure-sensitive adhesive layer B of the present invention may contain a silane coupling agent in order to improve the water resistance at the interface when applied to a hydrophilic adherend such as glass of a pressure-sensitive adhesive layer. The blending amount of the silane coupling agent is preferably 1 part by weight or less, more preferably 0.01 to 1 part by weight, and still more preferably 0.02 to 0.6 part by weight based on 100 parts by weight of the (meth) acrylic polymer. If the blending amount of the silane coupling agent is too large, the adhesive force to the glass increases to deteriorate the re-peelability, while if too small, the durability is deteriorated.

Examples of the silane coupling agent that can be preferably used include 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 2- (3,4- Epoxycyclohexyl) ethyltrimethoxysilane and the like epoxy group-containing silane coupling agents such as 3-aminopropyltrimethoxysilane, N-2- (aminoethyl) -3-aminopropylmethyldimethoxysilane, 3-triethoxysilyl Amino group-containing silane coupling agents such as N- (1,3-dimethylbutylidene) propylamine and N-phenyl- -aminopropyltrimethoxysilane, 3-acryloxypropyltrimethoxysilane, 3- (Meth) acrylic group-containing silane coupling agents such as trimethylolpropane tri (meth) acrylate and oxypropyl triethoxy silane, and isocyanate group-containing silane coupling agents such as 3-isocyanatopropyl triethoxy silane.

The pressure-sensitive adhesive for forming the pressure-sensitive adhesive layer A and the pressure-sensitive adhesive layer B of the present invention may contain other known additives such as polyether compounds of polyalkylene glycols such as polypropylene glycol, A leveling agent, a softening agent, an antioxidant, an antioxidant, a light stabilizer, an ultraviolet absorber, a polymerization inhibitor, an inorganic or organic filler, a metal powder, a particulate, a thin film, etc. May be suitably added depending on the use. In addition, within the controllable range, a redox system to which a reducing agent is added may be employed.

The pressure-sensitive adhesive layer A and the pressure-sensitive adhesive layer B can be formed, for example, by applying the forming material (pressure-sensitive adhesive) to a member such as a transparent gas and / or a polarizing film, and drying the polymerization solvent or the like. In coating the forming material, at least one solvent other than the polymerization solvent may be newly added.

As the coating method of the forming material, various methods are used. Specific examples include coating methods such as roll coating, kiss roll coating, gravure coating, reverse coating, roll brush, spray coating, dip roll coating, bar coating, knife coating, air knife coating, curtain coating, An extrusion coating method and the like.

The heating and drying temperature is preferably 40 to 200 ° C, more preferably 50 to 180 ° C, and particularly preferably 70 to 170 ° C. By setting the heating temperature within the above range, the pressure-sensitive adhesive layer A or the pressure-sensitive adhesive layer B having excellent pressure-sensitive adhesive properties can be obtained. The drying time is appropriate and an appropriate time can be employed. The drying time is preferably 5 seconds to 20 minutes, more preferably 5 seconds to 10 minutes, particularly preferably 10 seconds to 5 minutes.

The pressure-sensitive adhesive layer A and the pressure-sensitive adhesive layer B can be formed by polymerizing the above-mentioned forming material (pressure-sensitive adhesive) by irradiating active energy rays such as ultraviolet rays in the case of the active energy radiation curable pressure-sensitive adhesive. For ultraviolet irradiation, a high-pressure mercury lamp, a low-pressure mercury lamp, a metal halide lamp, or the like can be used.

Further, the pressure-sensitive adhesive layer A and the pressure-sensitive adhesive layer B can be formed on a support and then transferred to a polarizing film or the like. As the support, for example, a peeled sheet can be used. As the peeled sheet, a silicone release liner is preferably used. When the pressure-sensitive adhesive layer A is a multiple pressure-sensitive adhesive layer, the first pressure-sensitive adhesive layer (a), the second pressure-sensitive adhesive layer (b), and the like may be formed in order on the exfoliated sheet, The first pressure sensitive adhesive layer (a), the second pressure sensitive adhesive layer (b), and the like formed separately may be sequentially bonded to the polarizing film so that the first pressure sensitive adhesive layer (a) is the outermost surface.

The peeled sheet (separator) can be used as the separator SA ₁ of the pressure-sensitive adhesive layer A and the separator B of the pressure-sensitive adhesive layer B. In practical use, the peeled sheet is peeled off.

Examples of the constituent material of the separator include plastic films such as polyethylene, polypropylene, polyethylene terephthalate and polyester film, porous materials such as paper, cloth and nonwoven fabric, nets, foamed sheets, metal foils, A plastic film and the like can be mentioned, but a plastic film is suitably used because of its excellent surface smoothness.

The plastic film is not particularly limited as long as it is a film capable of protecting the pressure-sensitive adhesive layer A or the pressure-sensitive adhesive layer B, and examples thereof include a polyethylene film, a polypropylene film, a polybutene film, a polybutadiene film, A vinyl chloride film, a vinyl chloride copolymer film, a polyethylene terephthalate film, a polybutylene terephthalate film, a polyurethane film, and an ethylene-vinyl acetate copolymer film.

The separator may be formed by using the above plastic film as a base film and releasing and antifouling treatment with silicone, fluorine, long chain alkyl or fatty acid amide releasing agent, silica powder or the like, coating type, kneading type, It is also possible to perform an antistatic treatment. Particularly, the peeling property from the pressure-sensitive adhesive layer A and the pressure-sensitive adhesive layer B can be further enhanced by appropriately performing the peeling treatment such as the silicone treatment, the long-chain alkyl treatment, and the fluorine treatment on the surface of the separator.

Examples of the silicone type releasing layer include an addition reaction type silicone resin. KS-777, KS-778, KS-779H, KS-847H, KS-847T manufactured by Shinetsu Chemical Industry Co., Ltd., TPR-6700, TPR- And SD7220 and SD7226 manufactured by Toray, Dow Corning. The coating amount (after drying) of the silicone type releasing layer is preferably in the range of 0.01 to ² g / m ² , preferably 0.01 to 1 g / m ² , more preferably 0.01 to 0.5 g / m ² .

The release layer may be formed, for example, by coating the above-mentioned material on the oligomer-preventing layer by a conventionally known coating method such as reverse gravure coating, bar coating or die coating, and then heat- . If necessary, active energy ray irradiation such as heat treatment and ultraviolet irradiation may be used in combination.

The thickness of the separator (including the release layer) is usually about 5 to 200 mu m. Since the thickness of the separator is related to the peeling force, it is preferable to adopt the thickness corresponding to the separator. The thicknesses of the separators SA ₁ , SA ₁ 'and SA ₂ are preferably 30 μm or more, more preferably 40 μm or more, and further preferably 50 μm or more, in view of the peeling force and prevention of scratches. Specifically, the thickness of each of the separators SA ₁ , SA ₁ ', and SA ₂ is preferably 40 to 130 탆, more preferably 50 to 80 탆. The thickness of the separator SB is preferably 10 to 80 mu m, more preferably 20 to 50 mu m, further preferably 30 to 50 mu m, further preferably 30 to 40 mu m. In addition, in the configuration of a polarizing film over both sides of the pressure-sensitive adhesive layer, the thickness of the separator to combine with the case more than the thickness of the separator _{SA 1 (SA 1 ') 50㎛} , when the thickness of the separator is 30 to SB 50㎛ , Particularly in view of the peeling force and prevention of scratching.

Further, in forming the pressure-sensitive adhesive layer A and the pressure-sensitive adhesive layer B on the polarizing film, the surface of the polarizing film can be easily subjected to adhesion. Examples of the adhesion facilitating treatment include a corona treatment, a plasma treatment, an excimer treatment, a hard coating treatment and an undercoating treatment. Further, the surface of the pressure-sensitive adhesive layer may be subjected to an adhesive facilitating treatment. In the pressure-sensitive adhesive layer-coated polarizing film of the present invention, the surface of the polarizing film on which the pressure-sensitive adhesive layer A is laminated is preferably subjected to the adhesion facilitating treatment in view of peeling and foaming inhibition.

In the pressure-sensitive adhesive layer-coated polarizing film of the present invention, any one of the portions can be produced so as to have an antistatic function. The antistatic function can be imparted to the polarizing film with a pressure-sensitive adhesive layer, for example, by containing an antistatic agent in the polarizing film or the pressure-sensitive adhesive layer or separately forming an antistatic layer.

In the polarizing film with a pressure-sensitive adhesive layer of the present invention, the antistatic layer can be disposed on the viewing side of a polarizing film used for an image display apparatus (for example, a liquid crystal display apparatus) . As a result, problems such as deterioration of optical properties such as generation of bright spots due to polarized light dissipation and impurities that may occur when an antistatic layer (low surface resistivity layer) is formed between the polarizing film on the viewer side and the liquid crystal panel The reliability of the polarizing film provided on the most visible side is not impaired. In this way, it is possible to provide an antistatic function without deteriorating the performance of the image display apparatus.

In particular, it is effective when applied to a liquid crystal display device having a touch sensor, such as an in-cell type or an on-cell type, and can improve the quality of a liquid crystal display device with a touch sensor, such as an in-cell type or an on-cell type.

In order to impart the antistatic function to the pressure-sensitive adhesive forming the pressure-sensitive adhesive layer A and the pressure-sensitive adhesive layer B of the present invention, an ionic compound may be contained as an antistatic agent in addition to the base polymer. As the ionic compound, an alkali metal salt and / or an organic cation-anionic salt can be preferably used. The alkali metal salt may be an organic salt or an inorganic salt of an alkali metal. The term &quot; organic cation-anionic salt &quot; in the present invention means an organic salt, and the cation part thereof is composed of an organic material, and the anion part may be an organic material or an inorganic material. &Quot; Organic cation-anionic salt &quot; is also referred to as an ionic liquid, an ionic solid.

Examples of the ionic compound include inorganic salts such as ammonium chloride, aluminum chloride, copper chloride, ferrous chloride, ferric chloride and ammonium sulfate, in addition to the above alkali metal salts and organic cation-anionic salts. These ionic compounds may be used singly or in combination.

The ratio of the ionic compound in the pressure-sensitive adhesive forming the pressure-sensitive adhesive layer A and the pressure-sensitive adhesive layer B of the present invention is preferably 0.0001 to 5 parts by weight based on 100 parts by weight of the (meth) acrylic polymer. If the amount of the ionic compound is less than 0.0001 part by weight, the effect of improving antistatic performance may not be sufficient. The ionic compound is preferably at least 0.01 part by weight, more preferably at least 0.1 part by weight. On the other hand, if the amount of the ionic compound exceeds 5 parts by weight, the durability may be insufficient. The amount of the ionic compound is preferably 3 parts by weight or less, more preferably 1 part by weight or less. The above-mentioned upper limit value or lower limit value can be adopted as the ratio of the ionic compound to set a preferable range.

Example

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

&Lt; Production of polarizing film >

A polyvinyl alcohol film having a thickness of 80 占 퐉 was stretched to a stretch of 3 times while being dyed in a 0.3% strength iodine solution at 30 占 폚 for 1 minute between rolls having different speed ratios. Thereafter, the substrate was immersed in an aqueous solution containing boric acid at a concentration of 4% at 60 DEG C and potassium iodide at a concentration of 10% for 0.5 minutes, and the film was stretched to a total draw ratio of 6 times. Subsequently, the substrate was washed by immersion in an aqueous solution containing potassium iodide at a concentration of 1.5% at 30 DEG C for 10 seconds, and then dried at 50 DEG C for 4 minutes to obtain a polarizer having a thickness of 20 mu m. A triacetylcellulose film having a thickness of 40 占 퐉, saponified on one side of the polarizer, and an acrylic film having a thickness of 20 占 퐉 on the other side were bonded to each other with a polyvinyl alcohol adhesive to prepare a polarizing film. The surface (side of the triacetyl cellulose film) to which the pressure-sensitive adhesive layer B of the polarizing film was bonded was subjected to corona treatment as appropriate.

<Separator SA ₁ >

A release film obtained by forming the following release layer on a polyethylene terephthalate film having a thickness of 38 mu m, 50 mu m, or 75 mu m was used.

<Separator SA ₁ '

A release film obtained by forming the following release layer on a polyethylene terephthalate film having a thickness of 50 mu m was used.

<Separator SA ₂ >

A release film obtained by forming the following release layer on a polyethylene terephthalate film having a thickness of 50 mu m was used.

<Separator SB>

A release film obtained by forming the following release layer on a polyethylene terephthalate film having a thickness of 38 mu m, 50 mu m, or 75 mu m was used.

&Lt; Formation of release layer &

The following release layers were formed on the respective separators.

20 parts by weight of a silicone resin (KS-847H: Shin-Etsu Chemical Co., Ltd.) and 0.2 parts by weight of a curing agent (PL-50T: Shinetsugagaku) were diluted with 350 parts by weight of a methyl ethyl ketone / toluene mixed solvent To prepare a solution of a silicone-based releasing agent. A solution of the silicone release agent was applied to each of the above polyethylene terephthalate films (base film) by a gravure coater so as to have a thickness of 100 nm after drying, and then dried at 120 DEG C to form a release layer, Thereby obtaining a separator having a layer structure.

Production Example 1

&Lt; Preparation of forming material of pressure-sensitive adhesive layer A &

70 parts of 2-ethylhexyl acrylate (2EHA), 15 parts of N-vinylpyrrolidone (NVP), 4 parts of 4-hydroxybutylacrylate (NVP) were added to a four-necked flask equipped with a stirrer, a thermometer, , 15 parts of a photopolymerization initiator (4HBA), 0.05 parts of two photopolymerization initiators (trade name: Irgacure 184, BASF) and 0.05 parts of a photopolymerization initiator (trade name: Irgacure 651, BASF) To prepare a monomer mixture. Subsequently, the monomer mixture was partially photopolymerized in an ultraviolet ray under a nitrogen atmosphere to obtain a partial polymer (acrylic polymer syrup) having a polymerization degree of about 10%.

Then, 0.01 part of trimethylolpropane triacrylate (TMPTA) was added to 100 parts of the acrylic polymer syrup described above, and then they were uniformly mixed to prepare a material for forming the pressure-sensitive adhesive layer A (monomer component: A1).

Production Examples 2 to 5

(Monomer components A2 to A5) of the pressure-sensitive adhesive layer A were produced in the same manner as in Production Example 1 except that the composition of each component used in Production Example 1 was changed as shown in Table 1 Respectively.

In Table 1, 2EHA is 2-ethylhexyl acrylate;

NVP is N-vinylpyrrolidone;

4HBA is 4-hydroxybutyl acrylate;

TMPTA represents trimethylolpropane triacrylate.

&Lt; Fabrication of A-side Separator Adhesive Layer A >

The material (monomer component) of the pressure-sensitive adhesive layer A prepared in the above Production Example was coated on the release-treated surface of the separator SA ₁ shown in Table 2 or Table 3 so as to have a final thickness of 50 탆, 100 탆, 200 탆 or 300 탆 To form a coating layer. Subsequently, the separator SA ₂ shown in Table 2 or Table 3 was coated on the surface of the applied monomer component so that the releasably treated surface of the film became the coating layer side. Thereby, the coating layer of the monomer component was blocked from oxygen. Using a chemical light lamp (manufactured by Toshiba Kabushiki Kaisha), the sheet having the coating layer thus obtained was irradiated with ultraviolet light of an illuminance of 5 mW / cm ² (measured with a topcon UVR-T1 having a maximum sensitivity at about 350 nm) for 360 seconds , And the coating layer was cured to form a pressure-sensitive adhesive layer A to prepare a pressure-sensitive adhesive layer A with a double-side separator.

&Lt; Preparation of pressure-sensitive adhesive for forming pressure-sensitive adhesive layer B &

To a separable flask equipped with a thermometer, a stirrer, a reflux condenser and a nitrogen gas introducing tube, 99 parts of butyl acrylate (BA), 1 part of 4-hydroxybutyl acrylate (4HBA) as a monomer component, 0.2 part of isobutyronitrile and ethyl acetate as a polymerization solvent were added so that the solid content was 30%, nitrogen gas was introduced, and nitrogen substitution was carried out with stirring for about 1 hour. Thereafter, the flask was heated to 60 占 폚 and reacted for 7 hours to obtain an acrylic polymer having a weight average molecular weight (Mw) of 110,000. 0.1 part of trimethylolpropane xylylene diisocyanate ("Takenate D110N", manufactured by Mitsui Chemicals, Inc.) as an isocyanate-based crosslinking agent, 100 parts of a silane coupling agent (Shinetsugagaku Co., ), "KBM-403"), to prepare a pressure-sensitive adhesive composition (solution).

<Production of pressure sensitive adhesive layer B with a separator>

The pressure sensitive adhesive solution thus prepared was coated on the releasable surface of the separator SB shown in Table 2 or Table 3 so that the thickness after drying was 20 占 퐉 and heated and dried under normal pressure at 60 占 폚 for 3 minutes and at 120 占 폚 for 3 minutes, Aging was further carried out at 23 占 폚 for 120 hours to prepare a pressure-sensitive adhesive layer B.

&Lt; Production of single-sided pressure-sensitive adhesive layer B with polarizing film >

The separator SB-attached pressure-sensitive adhesive layer B with a separator SB was transferred to one surface (on the triacetyl cellulose film side) of the polarizing film to prepare a polarizing film with a single-side pressure-sensitive adhesive layer B.

Example 1

&Lt; Preparation of polarizing film with double-sided pressure-sensitive adhesive layer >

An apparatus as shown in Fig. 6 was used.

The pressure-sensitive adhesive layer A with double-side separators was peeled off the separator SA ₂ by the peeling roll together with the carrier from the delivery roll to convey the pressure-sensitive adhesive layer A with the separator SA ₁ . On the other hand, on the polarizing film side (acrylic film side) of the single-sided pressure-sensitive adhesive layer B-containing polarizing film conveyed separately from the delivery roll, the separator SA ₁ -dependent pressure-sensitive adhesive layer A was bonded by a pair of rolls, To prepare a polarizing film. During the bonding, the tension T1 of the single-sided separator-attached pressure-sensitive adhesive layer A and the tension T2 of the single-sided pressure-sensitive adhesive layer B were controlled as shown in Table 2.

In the production of the double-sided pressure-sensitive adhesive layer polarizing film over the separator SA _1, a separator SA _2, the peel force in the thickness of the separator SB separator SA ₁ a _1, the separator peeling force of SA ₂ a _2, peeling of the separator SB force b is As shown in Table 1.

The surface (on the triacetyl cellulose film side) to which the pressure-sensitive adhesive layer B of the polarizing film was bonded was subjected to corona treatment.

The thickness of the pressure-sensitive adhesive layer A is as shown in Table 1.

<Tension Measurement>

Using a sensing roll equipped with Nyrelex MB tension sensor (manufactured by NIPPON KOGYO CO., LTD.), The stress converted to a width of 1 m was measured.

Examples 2 to 13 and Comparative Examples 1 to 5

In Example 1, the thicknesses of the separator SA ₁ , the separator SA ₂ , the separator SB,

Separator peeling strength of a ₁ SA _1, SA ₂ separator peeling force of a _2, the peel force of the separator SB b,

The thickness of the pressure-sensitive adhesive layer A, the storage elastic modulus of the pressure-sensitive adhesive layer A (kind of pressure-sensitive adhesive)

The presence or absence of the corona treatment performed on the surface to which the pressure-sensitive adhesive layer A of the polarizing film is bonded,

Side pressure-sensitive adhesive layer A and the tension T2 of the single-sided pressure-sensitive adhesive layer B-side polarizing film were changed as shown in Table 1, and a double-sided pressure-sensitive adhesive layer- .

In Comparative Examples 1 and 2, the single-side pressure-sensitive adhesive layer B-polarized polarizing film and the separator SA ₁ -dependent pressure-sensitive adhesive layer A, which were prepared in each case, were used instead of the roll-to-roll film in a sheet film bonding apparatus manufactured by Sun Tech Co., The absorption axis was set to be a long side and bonded by an area of 500 mm x 400 mm.

Example 14

&Lt; Preparation of polarizing film with double-sided pressure-sensitive adhesive layer >

An apparatus as shown in Fig. 7 was used.

The double-sided pressure-sensitive adhesive layer polarizing film obtained in Comparative Example 3 was conveyed from the delivery roll, and the separator SA ₁ was peeled off by a peeling roll, and the polarizing film with the double-sided pressure-sensitive adhesive layer on which the separator SA ₁ was peeled was conveyed.

On the other hand, the curl adjusting separator SA ₁ 'conveyed separately from the delivery roll was bonded to the pressure-sensitive adhesive layer A of the polarizing film with double-sided pressure-sensitive adhesive layer by a pair of rolls to prepare a polarizing film with double-sided pressure-sensitive adhesive layer with roll-to-roll. In addition, when the joint is subjected to and controlled as described above shows the curl adjusting separator SA ₁ 'tension T3 and T4 tension the separator SA ₁ of the polarizing film over both sides of the pressure-sensitive adhesive layer is peeled off in the Table 3 below.

In the double-sided pressure-sensitive adhesive layer over the polarizing film, as shown in the separator ₁ SA peel force of the 'thickness of the separator of SA _1, a _1, which is described in Table 3.

Comparative Example 6

In Example 14, (change Comparative Example 3 to Example 2) double-sided pressure-sensitive adhesive layer polarizing film over the transport from the delivery roll, the curl adjusting separator SA ₁ 'tension T3 and the separator SA ₁ is a double-sided pressure-sensitive adhesive layer over the peeling of The same operation as in Example 14 was carried out except that the tensile strength T4 of the polarizing film was changed as shown in Table 3 to prepare a polarizing film with a double-sided pressure-sensitive adhesive layer.

The double-sided pressure-sensitive adhesive layer-containing polarizing films obtained in the above Production Examples, Examples and Comparative Examples were evaluated as follows. The evaluation results are shown in Table 1.

&Lt; Measurement of shear storage elastic modulus &

The shear storage modulus at 23 ° C was determined by dynamic viscoelasticity measurement. The measurement sample (pressure-sensitive adhesive layer A, pressure-sensitive adhesive layer B) was measured at a frequency of 1 Hz in a temperature range of -20 to 100 占 폚 using a dynamic viscoelasticity measuring apparatus (apparatus name "ARES", manufactured by T.A. And the shear storage modulus at 23 占 폚 was calculated at 5 占 폚 / min.

&Lt; Measurement of peeling force of separator >

A separator (release liner) was cut from the sample by a tensile tester at a peeling angle of 180 deg. And peeled off from the sample after cutting to a width of 50 mm and a length of 100 mm with a measurement sample (a separator-attached pressure-sensitive adhesive layer A with a separator, And the peel force (N / 50 mm) at the time of leaving at a speed of 300 mm / min was measured.

<Curl>

The double-sided pressure-sensitive adhesive layer-containing polarizing film was placed on a horizontal surface such that the curled surface of the polarized film was downwardly directed to the cut rectangular object of 300 mm in the absorption axis direction and 250 mm in the direction perpendicular to the absorption axis, The distance (mm) of the longest point from the horizontal plane was measured.

<Yield>

The separator SB was peeled off for the polarizing film (size: 70 mm x 100 mm) with the double-sided pressure-sensitive adhesive layer, and then the pressure-sensitive adhesive layer B side was bonded to a non-alkali glass (made by Corning Inc., 1737) having a thickness of 0.7 mm. This operation was performed ten times.

In the joining operation, it was confirmed whether or not the joining operation could be completed without causing a phenomenon in which air bubbles were entrained at the ends. The ratio (success rate) in the case where the phenomenon in which air bubbles are not generated at the ends does not occur is expressed by the following standard.

◎: Success rate 100%

○: Success rate 80 to less than 100%

DELTA: Success rate: 50 to less than 80%

×: Success rate less than 50%

&Lt; Evaluation method of level difference absorbency &

A sheet piece having a width of 50 mm and a length of 100 mm was cut out from the pressure-sensitive adhesive layer A with separators on both sides. One of the release films was peeled off from the sheet piece, and the pressure sensitive adhesive side of the sheet piece was bonded to a COP (cyclic polyolefin) film (thickness: 100 탆) using a hand roller.

Then, the other release film was peeled off from the sheet piece bonded to the COP film. The printing stepped glass plate was bonded under the following bonding conditions so that the pressure-sensitive adhesive layer on the COP film was in contact with the side where the printing step of the glass plate was applied. Then, an evaluation sample having the constitution of a COP film / pressure-sensitive adhesive layer / printing stepped glass plate was obtained.

(Bonding condition)

Surface pressure: 0.3 MPa

Attachment speed: 25mm / s

Roll rubber hardness: 70 °

The printing stepped glass plate was formed on one side of a glass plate (manufactured by Matsunami Glass Co., Ltd., length 100 mm, width 50 mm, thickness 0.7 mm) with a thickness of 50 μm or 80 μm Was used.

(Thickness of the step / pressure-sensitive adhesive layer) x 100 (%), which is an index showing the step difference absorbency, are 50% and 80%, respectively.

Subsequently, the sample for evaluation was placed in an autoclave and subjected to autoclave treatment at a pressure of 5 atm and a temperature of 50 캜 for 15 minutes. After the autoclave treatment, the sample for evaluation was taken out, and the state of bonding between the pressure-sensitive adhesive layer and the glass plate for printing step formation was visually observed, and the level difference absorbency was evaluated according to the following evaluation criteria.

○: No bubbles remain, no peeling occurs between the pressure-sensitive adhesive layer and the printing plate glass plate

X: Bubbles remain, and peeling occurs between the pressure-sensitive adhesive layer and the glass plate for forming the print step

<Durability>

The separator film of the pressure-sensitive adhesive layer A (visible side) of the pressure-sensitive adhesive layer-attached polarizing film obtained in each of the above examples was peeled off and adhered to a 0.7 mm-thick non-alkali glass (made by Corning Inc., 1737) using a laminator. Subsequently, the autoclave treatment was carried out at 50 DEG C and 0.5 MPa for 15 minutes to adhere the polarizing film with the pressure-sensitive adhesive layer completely to the alkali-free glass. Subsequently, vacuum bonding was performed at a pressure of 0.2 MPa and a degree of vacuum of 30 Pa using a vacuum bonding apparatus manufactured by LANTECH. This was put under the conditions of a heating oven (heating) of 85 ° C and 95 ° C and a constant-temperature and humidity (humidification) of 60 ° C / 95% RH, and the peeling of the polarizing film after 500 hours was evaluated based on the following criteria.

◎: No peeling was observed at all.

○: There was peeling that can not be confirmed by the naked eye.

△: A small peeling that can be confirmed by the naked eye was seen.

X: Clear peeling (exceeding 0.5 占 퐉) was observed.

As a result of Comparative Example 5, "with air bubbles" indicates that air bubbles were generated immediately after bonding because the storage elastic modulus of the pressure-sensitive adhesive layer A was high, so that after the cover glass was bonded, the ink level difference of the cover glass could not be completely covered.

Comparative Example 6 is a case in which the characteristics are deteriorated by the replacement bonding.

1 polarizing film
A pressure-sensitive adhesive layer A (visible side)
B pressure-sensitive adhesive layer B (opposite side of the viewer side)
C member (touch panel or transparent gas)
D display section (image display apparatus)
The separator of the SA ₁ pressure-sensitive adhesive layer A (visible side)
SA ₁ 'pressure sensitive adhesive layer A (visible side) separator for curl adjustment
The separator of the SA ₂ pressure-sensitive adhesive layer A (visible side)
The SB pressure-sensitive adhesive layer B (opposite side of the viewer side)
10, 10 'Double-sided pressure-sensitive adhesive layer Polarizing film
11 Adhesive layer with unidirectional separator A
12 one side pressure-sensitive adhesive layer B polarized polarizing film
13 Double-sided pressure-sensitive adhesive layer with separator SA ₁ peeled Polarizing film
14 Double-sided pressure sensitive adhesive layer A
2 pressure-sensitive adhesive layer (pressure-sensitive adhesive layer B)
3 Transparent conductive layer (antistatic layer)
4 glass substrate
5 liquid crystal layer
6 drive electrode
7 Antistatic layer and sensor layer
8 Driving electrode and sensor layer
9 sensor layer
a First pressure sensitive adhesive layer
b Second pressure sensitive adhesive layer

Claims (12)

And a pressure-sensitive adhesive layer (A) disposed on the viewer side of the polarizing film and an adhesive layer (B) disposed on the opposite side of the pressure-sensitive adhesive layer (A) Sensitive adhesive layer having a separator SA _{1 on} the pressure-sensitive adhesive layer A and a separator SB on the pressure-sensitive adhesive layer B,
The pressure-sensitive adhesive layer (A) has a storage elastic modulus at 23 캜 of 0.02 to 0.3 MPa,
The double-sided pressure-sensitive adhesive layer-containing polarizing film was placed on a horizontal plane so that the curled rectangular face was located on the lower side with respect to the cut rectangular product of 300 mm in the absorption axis direction of the polarizing film and 250 mm in the direction perpendicular to the absorption axis The curl amount measured by placing the separator SB side on the horizontal plane so that the separator SB side is on the horizontal plane is + and the curl measured by placing the separator SA ₁ on the horizontal plane so as to be the lower side) is -10 mm to +60 mm Sensitive adhesive layer. &Lt; / RTI &gt; The method according to claim 1,
Wherein the curl amount is + 2 mm to + 30 mm. 3. The method according to claim 1 or 2,
Wherein the separator (SA1 ₎ has a thickness of 50 占 퐉 or more, and the separator (SB) has a thickness of 30 to 55 占 퐉. 4. The method according to any one of claims 1 to 3,
The separator peeling strength of SA ₁ is a _1, the double-sided pressure-sensitive adhesive layer over the polarizing film, characterized in that is higher than the release force of the separator SB b. A method for producing a polarizing film with a double-sided pressure-sensitive adhesive layer according to any one of claims 1 to 4,
Side adhesive layer B having a polarizing film and a pressure-sensitive adhesive layer B provided on the most viewer side of the polarizing film used in the image display apparatus and having the separator SB in the pressure-sensitive adhesive layer B,
A one-side separator over the pressure-sensitive adhesive layer A having a pressure-sensitive adhesive layer A of 0.02 to 0.3MPa storage modulus over the separator 23 ℃ SA _1,
(1) of joining the pressure-sensitive adhesive layer A of the single-sided separator-attached pressure-sensitive adhesive layer A with a roll-to-roll process so that the pressure-sensitive adhesive layer A of the single-sided pressure-sensitive adhesive layer A with the single-sided separator is disposed on the polarizing film opposite to the side on which the pressure- Wherein the pressure-sensitive adhesive layer is a double-sided pressure-sensitive adhesive layer. 6. The method of claim 5,
By the process (a) of taking-off the one-side separator over the pressure-sensitive adhesive layer A is, the separator SA ₁ on one side of the pressure-sensitive adhesive layer A, from both sides of the separator the adhesive layer A over which the separator SA ₂ on the other side separator SA ₂ &Lt; tb &gt;
The separator SA peeling strength of ₁ a _1, the separator peeling force of SA ₂ a ₂ and double-sided pressure-sensitive adhesive layer over the polarizing film, characterized in that the release force of the separator SB b satisfy the relationship a _1> a ₂ ≥b &Lt; / RTI &gt; The method according to claim 6,
Peel force of the separator SA ₁ a _1, the separator, the peeling strength of SA ₂ a ₂ and over both sides of the pressure-sensitive adhesive layer, characterized in that the release force of the separator SB b satisfy the relationship a _1> 1.5a ₂ ≥1.5b A method for producing a polarizing film. 8. The method according to any one of claims 5 to 7,
In the step (1) of joining with roll-to-roll,
(T1 / T2) of the tensile force T1 of the single-sided separator-attached pressure-sensitive adhesive layer A and the tensile force T2 of the single-sided pressure-sensitive adhesive layer B-bonded polarizing film is controlled to 0.8 or more. 8. The method according to any one of claims 5 to 7,
Sensitive adhesive layer according to any one of claims 5 to 7,
Step (b) of peeling the separator SA ₁ from the obtained double-sided pressure-sensitive adhesive layer-containing polarizing film, and
(2) of joining the curl adjusting separator SA ₁ 'by a roll-to-roll process to the pressure-sensitive adhesive layer A of the polarizing film with the double-sided pressure-sensitive adhesive layer on which the separator SA ₁ is peeled off. Way. 10. The method of claim 9,
In the step (2) of joining with roll-to-roll,
The curl adjustment separator SA ₁ 'tension T3 and the separator SA ₁ of the polarizing film over the adhesive layer, characterized in that the control of the ratio (T3 / T4) of the tension T4 of the polarizing film over the peel-sided pressure-sensitive adhesive layer is set to be not less than 0.8 in Gt; 11. The method according to any one of claims 5 to 10,
Sensitive adhesive layer according to any one of claims 5 to 10,
(C) a step of cutting the obtained double-sided pressure-sensitive adhesive layer-containing polarizing film to an arbitrary size, and a step (d) of cutting the end of the cut polarized film with double-sided pressure-sensitive adhesive layer. &Lt; / RTI &gt; An image display device having at least one double-sided pressure-sensitive adhesive layer-attached polarizing film,
Sensitive adhesive layer-side polarizing film provided on the most viewer side of the polarizing film used in the image display apparatus is characterized in that the double-sided pressure-sensitive adhesive layer-containing polarizing film according to any one of claims 1 to 4 is laminated on the separator SA ₁ and the separator SB is removed,
Wherein the pressure-sensitive adhesive layer (A) of the double-sided pressure-sensitive adhesive layer-containing polarizing film is placed on the viewer side and the pressure-sensitive adhesive layer (B) is on the display portion side.

Images