JP2016136238A - Polarization film with double-sided adhesive layers, manufacturing method thereof and picture display unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polarization film with double-sided adhesive layers, having adhesive layers respectively on both sides of a polarization film arranged closest to a visible side in a picture display unit, the polarization film with double-sided adhesive layers having an excellent yield and capable of satisfying step absorbency.SOLUTION: A polarization film 1 with double-sided adhesive layers includes: a polarization film 1 arranged closest to a visible side; an adhesive layer A arranged on a visible side of the polarization film 1; and an adhesive layer B arranged on a side opposite to the adhesive layer A. The adhesive layer A includes a separator SA, and the adhesive layer B includes a separator SB. In the adhesive layer A, a storage elastic modulus at 23°C is from 0.02 to 0.3 MPa. In the polarization film 1 with double-sided adhesive layers, a curl amount is from -10 mm to +60 mm.SELECTED DRAWING: Figure 1a

Description

  The present invention relates to a polarizing film with a double-sided pressure-sensitive adhesive layer having pressure-sensitive adhesive layers on both sides of a polarizing film provided on the most visible side in a polarizing film used in an image display device, and a method for producing the same. Moreover, this invention relates to the image display apparatus by which the said polarizing film with a double-sided adhesive layer is arrange | positioned at the visual recognition 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 electronic paper.

  The polarizing film with a double-sided pressure-sensitive adhesive layer of the present invention has pressure-sensitive adhesive layers on both sides of the polarizing film, and the pressure-sensitive adhesive layer on the viewing side is, for example, an input such as a touch panel applied on the viewing side of the image display device. It can be suitably applied to a member such as a transparent substrate such as an apparatus, a cover glass, or a plastic cover. On the other hand, the pressure-sensitive adhesive layer on the side opposite to the viewing side is applied to the display unit of the image display device. As said touch panel, it can use suitably for touch panels, such as an optical system, an ultrasonic system, an electrostatic capacitance system, and a resistive film system. In particular, it is suitably used for a capacitive touch panel. Although the said touch panel is not specifically limited, For example, it is used for a mobile telephone, a tablet computer, a portable information terminal, etc.

  In a liquid crystal display device or the like, it is indispensable to dispose polarizing elements on both sides of the liquid crystal cell because of its image forming method, and a polarizing film is generally attached. For sticking the polarizing film to the display unit side such as a liquid crystal cell, an adhesive is usually used. In such a case, since the adhesive has the merit that a drying step is not required to fix the polarizing film, the adhesive is a polarizing film with an adhesive layer provided in advance as an adhesive layer on one side of the polarizing film. A film is generally used. Various things are proposed as a polarizing film with an adhesive layer (patent documents 1 and 2). As for these polarizing films with an adhesive layer, the adhesive layer side is applied to display parts, such as a liquid crystal cell.

  On the other hand, on the viewing side of the polarizing film, members such as an input device such as a touch panel, a transparent substrate such as a cover glass and a plastic cover are provided. The members are also generally bonded together by an adhesive layer (Patent Document 3).

JP 2004-170907 A JP 2006-053531 A JP 2002-348150 A

  As described in Patent Documents 1 and 2, the polarizing film with the pressure-sensitive adhesive layer provided on the most visible side in the polarizing film used in the image display device has the pressure-sensitive adhesive layer of the polarizing film with the pressure-sensitive adhesive layer bonded to the display unit. The On the other hand, when a member such as a transparent substrate is provided on the viewing side of the polarizing film with the pressure-sensitive adhesive layer (what is provided on the most visible side), the polarizing film of the polarizing film with the pressure-sensitive adhesive layer is separately described in Patent Document 3. Thus, after preparing the adhesive sheet for intermediate films and bonding this as an adhesive layer, members, such as a transparent base | substrate, are further bonded to the said adhesive layer. As described above, a plurality of steps are required to further bond a member such as a transparent substrate to the polarizing film closest to the viewing side in the polarizing film used in the image display device.

  Patent Documents 1 and 2 disclose a polarizing film with a pressure-sensitive adhesive layer having a pressure-sensitive adhesive layer on both sides of the polarizing film (full lamination: polarizing film with a double-sided pressure-sensitive adhesive layer). However, when the polarizing film with a double-sided pressure-sensitive adhesive layer is bonded to an adherend (a member such as a transparent substrate on the viewing side and a display portion on the opposite side), air bubbles are caught at the end of the bonding surface. Therefore, the workability is not sufficient and the yield is not sufficient. Therefore, in the polarizing film with a double-sided pressure-sensitive adhesive layer, not only simplification of the process but also improvement in workability and yield improvement are required.

  Further, the surface of a member such as the transparent substrate such as the cover glass has a step caused by the printing ink. Therefore, when the member having the step surface and another member are bonded together with the adhesive layer, the adhesive layer absorbs the step and the adhesive layer follows the step so that there is no gap between the members. Is required. As an index of the pressure-sensitive adhesive layer related to the step, the step absorbency (%) represented by the step (μm) and the thickness (μm) of the pressure-sensitive adhesive layer: (step / thickness of the pressure-sensitive adhesive layer) × 100 And satisfying the following ability. About 20% was required as the step absorbability. In recent years, the level difference absorbability requirement has become as high as 30%. In general, in order to absorb the step, it is conceivable to lower the elastic modulus of the pressure-sensitive adhesive layer to make it softer. However, if the pressure-sensitive adhesive layer is softened, the workability is poor and a lot of glue stains are generated, and handling properties are improved. This is not preferable.

  On the other hand, when the pressure-sensitive adhesive layer of the polarizing film with a double-sided pressure-sensitive adhesive layer (the side on which a member such as a transparent substrate is bonded) is hardened, the step absorbability is reduced by full lamination, and foaming is more likely to occur with reliability. It was a thing.

  Therefore, the present invention is a polarizing film with a double-sided pressure-sensitive adhesive layer having a pressure-sensitive adhesive layer on both sides of the polarizing film provided on the most visible side in the polarizing film used in the image display device, and the yield is good, and It aims at providing the polarizing film with a double-sided adhesive layer which can satisfy level | step difference absorbency, and its manufacturing method.

  Another object of the present invention is to provide an image display device having the polarizing film with the double-sided pressure-sensitive adhesive layer.

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

That is, this invention is arrange | positioned on the opposite side of the polarizing film provided in the visual recognition side most, the adhesive layer A arrange | positioned at the visual recognition side of the said polarizing film, and the said adhesive layer A in the polarizing film used for an image display apparatus. A polarizing film with a double-sided pressure-sensitive adhesive layer having a pressure-sensitive adhesive layer B and having a separator SA _{1 in} the pressure-sensitive adhesive layer A and a separator SB in the pressure-sensitive adhesive layer B,
The pressure-sensitive adhesive layer A has a storage elastic modulus at 23 ° C. of 0.02 to 0.3 MPa,
The polarizing film with a double-sided pressure-sensitive adhesive layer is such that a curled convex surface is on the lower side of a rectangular object that is 300 mm in the absorption axis direction of the polarizing film and 250 mm in the direction perpendicular to the absorption axis. amount curl was measured by placing on a horizontal surface (however, the curl amount measured by placing on a horizontal surface so that the side becomes below the separator SB +, a horizontal plane so that the side of the separator SA ₁ on the lower side The polarizing film with a double-sided pressure-sensitive adhesive layer is characterized in that the curl amount measured by placing it on the surface is displayed as-, and is -10 mm to +60 mm.

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

In the double-sided pressure-sensitive adhesive layer-attached polarizing film, the separator SA ₁ is a thickness of 50μm or more, the separator SB is preferably has a thickness of 30～55Myuemu.

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

The present invention is also a method for producing the polarizing film with a double-sided pressure-sensitive adhesive layer,
A polarizing film with a one-side pressure-sensitive adhesive layer B having a polarizing film and a pressure-sensitive adhesive layer B provided on the most visible side in a polarizing film used for an image display device, and having a separator SB in the pressure-sensitive adhesive layer B;
A pressure-sensitive adhesive layer A with a one-side separator having a pressure-sensitive adhesive layer A having a storage elastic modulus at 23 ° C. of 0.02 to 0.3 MPa on the separator SA ₁
Roll toe so that the pressure-sensitive adhesive layer A of the pressure-sensitive adhesive layer A with the one-side separator is disposed on the polarizing film on the side opposite to the side where the pressure-sensitive adhesive layer B is provided in the polarizing film with the one-side pressure-sensitive adhesive layer B. The manufacturing method of the polarizing film with a double-sided adhesive layer characterized by including the process (1) bonded together with a roll.

In the method for producing a polarizing film with a double-sided pressure-sensitive adhesive layer, the pressure-sensitive adhesive layer A with a single-side separator is a pressure-sensitive adhesive with double-sided separator having the separator SA ₁ on one side of the pressure-sensitive adhesive layer A and the separator SA ₂ on the other side. from adhesive layer a, it is those obtained by the step (a) peeling the separator SA _2,
Peel force _{a 1} of the separator SA _1, peel strength _{a 2} of the separator SA _2, peel force b of the separator SB is _preferably satisfies the a 1> _{a 2} ≧ b, the relationship.

In the production method of the polarizing film with double-sided pressure-sensitive adhesive layer, the peel force _{a 1} of the separator SA _1, peel strength _{a 2} of the separator SA _2, peel force b of the separator SB _is, a 1> 1.5a ₂ ≧ It is preferable to satisfy the relationship of 1.5b.

In the step (1) of laminating with the roll-to-roll in the method for producing the polarizing film with a double-sided pressure-sensitive adhesive layer,
It is preferable to control the ratio (T1 / T2) of the tension T1 of the pressure-sensitive adhesive layer A with one side separator and the tension T2 of the polarizing film with the one-side pressure sensitive adhesive layer B to 0.8 or more.

The manufacturing method of the polarizing film with the double-sided pressure-sensitive adhesive layer is continued,
Step from the obtained polarizing film double-sided pressure-sensitive adhesive layer is peeled off the separator SA ₁ (b), and,
A step (2) in which the curl adjusting separator SA ₁ ′ is bonded to the pressure-sensitive adhesive layer A of the polarizing film with a double-sided pressure-sensitive adhesive layer from which the separator SA ₁ has been peeled off by roll-to-roll.

In the step (2) of laminating with the roll-to-roll in the method for producing a polarizing film with a double-sided pressure-sensitive adhesive layer,
It is preferable that the ratio (T3 / T4) of the tension T3 of the curl adjusting separator SA ₁ ′ and the tension T4 of the polarizing film with a double-sided pressure-sensitive adhesive layer from which the separator SA ₁ has been peeled is controlled to 0.8 or more.

The manufacturing method of the polarizing film with the double-sided pressure-sensitive adhesive layer is continued,
A step (c) of cutting the obtained polarizing film with a double-sided pressure-sensitive adhesive layer into an arbitrary size and a step (d) of cutting an end of the cut polarizing film with a double-sided pressure-sensitive adhesive layer can be included.

Further, the present invention is an image display device having at least one polarizing film with a double-sided pressure-sensitive adhesive layer,
Most polarizing film double-sided pressure-sensitive adhesive layer provided on the viewing side in the polarizing film used in the image display apparatus is from the polarizing film with double-sided pressure-sensitive adhesive layer obtained by removing the separator SA ₁ and the separator SB,
It is related with the image display apparatus characterized by arrange | positioning so that the adhesive layer A of the said polarizing film with a double-sided adhesive layer may be in a visual recognition side, and the adhesive layer B may become a display part side.

  In the image display device, a member such as a transparent substrate such as a cover glass may be disposed further on the viewing side than the viewing-side polarizing film. Conventionally, the pressure-sensitive adhesive layer and then the above-mentioned member were laminated on the polarizing film on the viewing side, but the polarizing film with the pressure-sensitive adhesive layer of the present invention is a pressure-sensitive adhesive that is bonded to a member such as a transparent substrate on one side of the polarizing film. A polarizing film with a double-sided pressure-sensitive adhesive layer having a pressure-sensitive adhesive layer to be bonded to the display unit on the opposite side, and a pressure-sensitive adhesive layer on the viewing side of the polarizing film. Can be simplified. Moreover, according to the polarizing film which provided the adhesive layer on both surfaces beforehand, an improvement in productivity and an improvement in quality can be achieved by processing this into a predetermined size.

Further, the polarizing film with double-sided pressure-sensitive adhesive layer of the present invention, a separator SA 1 on both surfaces of the pressure-sensitive adhesive layer A and adhesive layer _B, and includes a separator SB, by the separator SA ₁ and the separator SB etc., the amount of curl Is controlled to be a predetermined amount. By controlling the curling amount in this way, when the polarizing film with a double-sided pressure-sensitive adhesive layer is bonded to the display unit, and further when a member such as a transparent substrate is bonded, bubbles are caught at the end of the bonding surface. Can be suppressed, workability can be improved, and yield can be improved.

  Moreover, in the polarizing film with a double-sided pressure-sensitive adhesive layer of the present invention, the storage elastic modulus of the pressure-sensitive adhesive layer A (the pressure-sensitive adhesive layer to which a member such as a transparent substrate such as a cover glass is attached) arranged on the viewing side of the polarizing film is predetermined. Since it is controlled within the range, there is no problem of glue stains and the handling property is good. Moreover, according to the pressure-sensitive adhesive layer in which the storage elastic modulus is controlled within a predetermined range, it is possible to suppress a decrease in step absorbency caused by full lamination and to suppress durability related to reliability (inhibition of foaming). Can do.

  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 without gaps following the steps. Even when the member such as the transparent substrate is a member having a step on the surface, the multiple pressure-sensitive adhesive layer can be bonded without following the step.

  The polarizing film with a double-sided pressure-sensitive adhesive layer of the present invention is obtained, for example, by sticking a pressure-sensitive adhesive layer A with a single-sided separator having a pressure-sensitive adhesive layer A and a polarizing film with a single-sided pressure-sensitive adhesive layer B having a separator B by roll-to-roll. It can be manufactured by the process of combining, and by the process of bonding with the roll-to-roll, the handling property can be improved and paste stains can be suppressed, and further, the workability of the obtained polarizing film with a double-sided pressure-sensitive adhesive layer can be improved. Can be improved.

Moreover, in the process of bonding together by the said roll toe roll, by controlling each tension | tensile_strength of the said adhesive layer A with a one side separator and the said polarizing film with a one side adhesive layer B, of the polarizing film with a double-sided adhesive layer obtained The curl amount can be controlled to be a predetermined amount. Further, it is possible to control as in the polarizing film with double-sided pressure-sensitive adhesive layer, a predetermined amount of curling of the polarizing film with double-sided pressure-sensitive adhesive layer also by replacing attaching the separator SA _1.

It is sectional drawing which shows typically one Embodiment of the polarizing film with a double-sided adhesive layer of this invention. It is sectional drawing which shows typically one Embodiment of the polarizing film with a double-sided adhesive layer of this invention. It is sectional drawing which shows typically the curl amount of the polarizing film with a double-sided adhesive layer of this invention. It is sectional drawing which shows typically the curl amount of the polarizing film with a double-sided adhesive layer of this invention. It is a conceptual diagram which shows typically the state by which members, such as an image display apparatus and a transparent base | substrate, are bonded via the polarizing film with a double-sided adhesive layer of this invention. It is sectional drawing which shows typically one Embodiment of an image display apparatus. It is sectional drawing which shows typically one Embodiment of an image display apparatus. It is sectional drawing which shows typically one Embodiment of an image display apparatus. It is sectional drawing which shows typically one Embodiment of the adhesive layer A with a both-sides separator. In the manufacturing method of the polarizing film with a double-sided adhesive layer of this invention, it is sectional drawing which shows typically one Embodiment of the process (1) bonded together by roll to roll. In the manufacturing method of the polarizing film with a double-sided adhesive layer of this invention, it is sectional drawing which shows typically one Embodiment of the process (2) of bonding the roll toe roll using the separator for curl adjustment.

  Hereinafter, embodiments of the polarizing film with a double-sided pressure-sensitive adhesive layer 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.

As shown in FIGS. 1 a and 1 b, the polarizing film 10 (10 ′) with a double-sided pressure-sensitive adhesive layer of the present invention has a polarizing film 1 and a pressure-sensitive adhesive layer A and a pressure-sensitive adhesive layer B on both sides of the polarizing film 1. Have. Moreover, the double-sided pressure-sensitive adhesive layer-equipped polarizing film 10 (10 ′) of the present invention is provided with a separator SA _{1 in} the pressure-sensitive adhesive layer A and a separator SB in the pressure-sensitive adhesive layer B. As the separator SA ₁ , a curl adjusting separator SA ₁ ′ described later can be used.

  In FIG. 1a, the case where the pressure-sensitive adhesive layer A is one layer is illustrated, but the pressure-sensitive adhesive layer A is formed from the outermost surface side (viewing side) to the first pressure-sensitive adhesive layer (a) and the second pressure-sensitive adhesive layer. It can be set as the multiple adhesive layer which has (b) in these order. In FIG. 1b, the 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) is illustrated. Although there is no restriction | limiting in the number of layers of the multiple adhesive layer based on the said adhesive layer A, Usually, about 5 layers can be provided. The number of multiple pressure-sensitive adhesive layers is preferably 2 to 4 layers, more preferably 2 to 3 layers. Each of the multiple pressure-sensitive adhesive layers is provided in direct contact with each other.

  In the multiple pressure-sensitive adhesive layer, a pressure-sensitive adhesive layer having a different composition is used for an adjacent pressure-sensitive adhesive layer, and a pressure-sensitive adhesive layer having the same composition can be used for a pressure-sensitive adhesive layer that is not adjacent. In FIG. 1b, the first pressure-sensitive adhesive layer (a) and the second pressure-sensitive adhesive layer (b) have different compositions. When 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 first pressure-sensitive adhesive layer The agent layer (a) and the second pressure-sensitive adhesive layer (b) have different compositions, 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) and the third pressure-sensitive adhesive layer The agent layer (c) may have the same composition.

2a and 2b are cross-sectional views schematically showing the curl amount of the polarizing film with double-sided pressure-sensitive adhesive layer 10 (10 ') of the present invention. The measurement of the amount of curl is performed on the rectangular film with the double-sided pressure-sensitive adhesive layer-attached polarizing film 10 (10 ′) cut out by 300 mm in the absorption axis direction of the polarizing film 1 and 250 mm in the direction perpendicular to the absorption axis. As shown in FIGS. 2a and 2b, the curl amount is measured by placing it on a horizontal plane such that the surface on which the curl is convex is on the lower side. In addition, the curl amount was measured by placing the separator SB side of the polarizing film 10 (10 ′) with the double-sided pressure-sensitive adhesive layer on the horizontal plane as shown in FIG. Is displayed as “+”, and as shown in FIG. 2B, the curl amount (h) measured by placing the separator SA ₁ (SA ₁ ′) on the horizontal plane so as to be on the lower side is displayed as “−”. Is done. The curl amount (h) is the distance (mm) of the longest point from the horizontal plane among the four points of the 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 curl amount (h) is preferably “+” as shown in FIG. 2a from the viewpoints of workability and yield, and is preferably +2 mm to +30 mm, more preferably +5 mm to +20 mm.

<Adhesive layer>
Hereinafter, the pressure-sensitive adhesive layer A and the pressure-sensitive adhesive layer B of the present invention will be described. Note that the pressure-sensitive adhesive layer A and the pressure-sensitive adhesive layer B are both “transparent” and can be satisfied by having a haze value measured at a thickness of 25 μm of 2% or less. The haze value is preferably 0 to 1.5%, and more preferably 0 to 1%.

<Thickness of adhesive layer>
Moreover, it is preferable that the whole thickness of the said adhesive layer A is 5 micrometers-1 mm. The total thickness of the pressure-sensitive adhesive layer A can be appropriately designed depending on the location where the pressure-sensitive adhesive layer A is applied. The total thickness of the pressure-sensitive adhesive layer A is preferably 10 μm to 500 μm, more preferably 20 μm to 300 μm.

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

  As shown in FIG. 1b, when the pressure-sensitive adhesive layer A has a two-layer structure of a first pressure-sensitive adhesive layer (a) and a second pressure-sensitive adhesive layer (b), the thickness of the first pressure-sensitive adhesive layer (a) is It is preferably 3 to 200 μm, more preferably 5 to 100 μm, and further preferably 10 to 75 μm. The thickness of the second pressure-sensitive adhesive layer (b) is preferably 10 to 300 μm, more preferably 20 to 150 μm, and further preferably 50 to 100 μm. Moreover, it is preferable that the difference of the thickness of a 1st adhesive layer (a) and the thickness of a 2nd adhesive layer (b) is 20-270 micrometers from the point of level | step difference absorbability and workability, Furthermore, it is 30-200 micrometers. Preferably there is.

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

<Storage elastic modulus of adhesive layer>
The pressure-sensitive adhesive layer A has a storage elastic modulus at 23 ° C. controlled to 0.02 to 0.3 MPa. Adhesive stains can be suppressed by the pressure-sensitive adhesive layer A whose storage elastic modulus is controlled in such a range, and the workability of bonding to a transparent substrate can be improved to improve the yield. The storage elastic modulus is preferably 0.02 to 0.4 MPa, more preferably 0.03 to 0.3 MPa, and further preferably 0.05 to 0.1 MPa. Control of the storage elastic modulus of the pressure-sensitive adhesive layer A is also preferable for satisfying the step absorbability.

<Peeling strength of 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 peeling force a ₁ of the separator SA ₁ (SA ₁ ′) with respect 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, Is preferably 0.1 to 1 N / 50 mm. Moreover, it is preferable that the peeling force b of the said separator SB with respect to the said adhesive layer B is 0.01-5 N / 50mm, Furthermore, it is preferable that it is 0.05-2 N / 50mm, Furthermore, 0.1-0.1 It is preferably 1 N / 50 mm.

Moreover, it is preferable that the peeling force a ₁ of the separator SA ₁ (SA ₁ ′) is adjusted so as to be higher than the peeling force b of the separator SB from the viewpoint of being bonded to the display panel first. 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 from the viewpoint of preventing defective peeling, and more preferably 0.02 It is preferably ˜1 N / 50 mm.

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

As shown in FIG. 3, the polarizing film with a double-sided pressure-sensitive adhesive layer of the present invention is applied to an image display device from which the separator SA ₁ (SA ₁ ′) and the separator SB are removed. The polarizing film which concerns on the polarizing film with a double-sided adhesive layer of this invention is applied as a polarizing film provided in the visual recognition side most in the polarizing film used for an image display apparatus. The said adhesive layer A of the polarizing film with a double-sided adhesive layer of this invention is arrange | positioned at the visual recognition side of an image display apparatus, and is bonded by member C, such as a transparent base | substrate. The pressure-sensitive adhesive layer B is disposed on the opposite side of the pressure-sensitive adhesive layer A in the polarizing film 1 and is bonded to the display unit D.

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

  The display unit D forms part of an image display device together with at least one polarizing film 1, and includes a liquid crystal display device, an organic EL (electroluminescence) display device, a PDP (plasma display panel), electronic paper, and the like. Can be given. As the display part D, the liquid crystal display device which has the liquid crystal layer 5 used with the polarizing film 1 can be used conveniently. 4a to 4c are cross-sectional views schematically showing a typical embodiment of an image display device (liquid crystal display device) to which the polarizing film with an adhesive layer of the present invention is applied. In the image display devices (liquid crystal display devices) shown in 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 has a cover glass C / adhesive layer A / polarizing film 1 (viewing side) / adhesive layer 2 (B) / antistatic layer 3 / glass substrate 4 / liquid crystal layer. 5 / drive electrode 6 / glass substrate 4 / adhesive layer 2 / polarizing film 1 The antistatic layer 3 and the drive electrode 6 can be formed of a transparent conductive layer. The antistatic layer 3 can be arbitrarily formed.

  The image display device (liquid crystal display device) shown in FIG. 4b is a case where the transparent conductive layer is used as an electrode for a touch panel (in-cell type touch panel), and covers glass C / adhesive layer A / polarizing film 1 (viewing side). / Adhesive layer 2 (B) / Antistatic layer / sensor layer 7 / Glass substrate 4 / Liquid crystal layer 5 / Drive electrode / sensor layer 8 / Glass substrate 4 / Adhesive layer 2 / Polarizing film 1 The antistatic layer / sensor layer 7 and the drive electrode / 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 for a touch panel (on-cell type touch panel), and covers glass C / adhesive layer A / polarizing film 1 / adhesive layer. 2 (B) / antistatic layer / sensor layer 7 / sensor layer 9 / glass substrate 4 / liquid crystal layer 5 / drive electrode 6 / glass substrate 4 / adhesive layer 2 / polarizing film 1 The antistatic layer / sensor layer 7, the sensor layer 9, and the drive electrode 6 can be formed of a transparent conductive layer.

  As the polarizing film, one having a transparent protective film on one side or both sides of a polarizer is generally used. The transparent protective film in the polarizing film can be provided with a functional layer such as a hard coat layer. 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 appropriately used for the image display device. Examples of the optical film include liquid crystal display devices such as a reflection plate, an anti-transmission plate, a retardation plate (including wavelength plates such as 1/2 and 1/4), an optical compensation film, a visual compensation film, and a brightness enhancement film. What becomes an optical layer which may be used for formation of is mentioned. These can be used alone as an optical film, or can be laminated on the polarizing film for practical use to use one layer or two or more layers.

  4A to 4C, the pressure-sensitive adhesive layer 2 is disclosed for bonding with other members such as a liquid crystal cell (glass substrate). The pressure-sensitive adhesive layer 2 on the viewing side (upper side) of the liquid crystal cell is applied as a pressure-sensitive adhesive layer B. For the pressure-sensitive adhesive layer 2, for example, various pressure-sensitive adhesives based on polymers such as acrylic polymers, silicone polymers, polyesters, polyurethanes, polyamides, polyethers, fluorine-based and rubber-based polymers may be appropriately selected and used. it can. In particular, an acrylic pressure-sensitive adhesive having excellent optical transparency, moderate wettability, cohesiveness, and adhesive pressure-sensitive adhesive properties, and excellent weather resistance and heat resistance is preferable.

  Generally, a liquid crystal display device incorporates a drive circuit by appropriately assembling components such as a liquid crystal cell (glass substrate / liquid crystal layer / glass substrate), polarizing films disposed on both sides thereof, and an illumination system as required. And so on. As the liquid crystal cell, any type such as a TN type, STN type, π type, VA type, IPS type, or the like can be used. In addition, an appropriate liquid crystal display device such as a lighting system using a backlight or a reflecting plate can be formed. Further, when forming a liquid crystal display device, for example, a single layer or a suitable part such as a diffusing plate, an antiglare layer, an antireflection film, a protective plate, a prism array, a lens array sheet, a light diffusing plate, a backlight, etc. Two or more layers can be arranged.

  As the member C, a touch panel can be used. The touch panel C is a capacitive touch panel, and a transparent substrate, an adhesive layer 2 and a transparent conductive film are laminated in this order. Further, two or more transparent conductive films can be laminated. The transparent substrate can have a sensor layer. The transparent substrate can be applied alone to an image display device (liquid crystal display device) as a cover glass or a plastic cover. In addition, a hard coat film can be provided on the transparent conductive film on the side opposite to the transparent substrate of the touch panel C.

  Examples of the transparent substrate include a glass plate and a transparent acrylic plate (PMMA plate). The transparent substrate is a so-called cover glass and can be used as a decorative panel. The transparent conductive film is preferably a glass plate or a transparent plastic film (particularly a PET film) provided with a transparent conductive film. Examples of the transparent conductive film include a thin film made of a metal, a metal oxide, or a mixture thereof, and examples thereof include a thin film of ITO (indium tin oxide), ZnO, SnO, and CTO (cadmium tin oxide). The thickness of the transparent conductive film is not particularly limited, but is about 10 to 200 nm. A typical example of the transparent conductive film is an ITO film in which an ITO film is provided on a PET film. The transparent conductive film can be provided via an undercoat layer. A plurality of undercoat layers can be provided. An oligomer migration preventing layer can be provided between the transparent plastic film substrate and the pressure-sensitive adhesive layer. The hard coat film is preferably one obtained by subjecting a transparent plastic film such as a PET film to a hard coat treatment.

The polarizing film 10 with double-sided pressure-sensitive adhesive layer of the present invention has, for example, the polarizing film 1 and the pressure-sensitive adhesive layer B, and the polarizing film 12 with one-side pressure-sensitive adhesive layer B provided with the separator SB in the pressure-sensitive adhesive layer B. When the separator SA ₁ with side separator pressure-sensitive adhesive layer having an adhesive layer a on a (11), opposite the side where the adhesive layer B is provided in the side pressure-sensitive adhesive layer B Tsukehen light film 12 It can manufacture by sticking together so that the adhesive layer A of the said adhesive layer A (11) with a one-sided separator may be arrange | positioned at the polarizing film 1. FIG. As shown in FIG. 6, it is preferable to perform the said manufacturing method by the process (1) bonded together by roll toe roll. In FIG. 6, the polarizing film 12 with the one side adhesive layer B and the adhesive layer A (11) with one side separator conveyed from a delivery roll are bonded between a pair of bonding rolls R1 and R2 (1). The polarizing film 10 with a double-sided pressure-sensitive adhesive layer is obtained by a take-up roll.

Further, the urging side separator pressure-sensitive adhesive layer A (11) is to obtain a separator SA ₁ on one side of the pressure-sensitive adhesive layer A, from other side separator SA ₂ Both sides separator pressure-sensitive adhesive layer having a A (14) it can. As shown in FIG. 5, the double-sided separator-attached pressure-sensitive adhesive layer A (14) can be represented by a configuration of separator SA ₁ / pressure-sensitive adhesive layer A / separator SA ₂ . In Figure 6, delivery Both sides separator adhesive layer is conveyed from the roll A (14) is by the peeling roll R3, is subjected step of peeling the separator SA ₂ (a) is, in step (1) to be bonded, One side separator-attached pressure-sensitive adhesive layer A (11) is supplied.

When using the both side separator pressure-sensitive adhesive layer A (14), the peel force _{a 1} of the separator SA _1, peel strength _{a 2} of the separator SA _2, peel force b of the separator SB _is a 1> _{a 2} It is preferable to satisfy the relationship of ≧ b from the viewpoint of the order of the product process and the order of the bonding process to a liquid crystal panel, an organic EL panel or the like. Furthermore, the release force _{a 1} of the separator SA _1, peel strength _{a 2} of the separator SA _2, peel force b of the separator SB _is a 1> 1.5a ₂ ≧ 1.5b, to satisfy the relation Is preferable from the viewpoint of improving workability.

Peel force _{a 1} of the separator SA _1, peel strength b of the separator SB is as described above. Preferably the peel force _{a 2} of the separator SA ₂ is 0.01~5N / 50mm, still more preferably a 0.05~2N / 50mm, even at 0.05~1N / 50mm Is preferred. Is preferably the difference in release force _{a 2} release force _{a 1} and the separator SA ₂ of the separator SA ₁ is 0.01~1N / 50mm in view of workability in bonding step to the polarizing plate, and further 0.03-0.5 N / 50 mm is preferable.

  Moreover, the polarizing film 10 with a double-sided adhesive layer of this invention WHEREIN: In the process (1) bonded together by the said roll toe roll, tension | tensile_strength T1 of the said adhesive layer A (11) with a separator, and the said one-side adhesive layer B polarized light It is preferable to control the ratio (T1 / T2) of the tension T2 of the film 12 to 0.8 or more. In FIG. 6, the tension T1 and the tension T2 can be controlled by rolls R11 and R12.

  The curl amount can be adjusted by controlling the tension ratio (T1 / T2) within the range. 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) becomes too large, the curl amount becomes too large, and the bonding accuracy is lowered in the bonding process to the panel. Therefore, the tension ratio (T1 / T2) is 10 or less. It is preferably 6 or less, more preferably 4 or less.

The tension T1 is preferably 8 to 500 N / m, more preferably 50 to 300 N / m, and even more preferably 100 to 200 N / m.
The tension T2 is preferably 10 to 400 N / m, more preferably 20 to 200 N / m, and further preferably 40 to 100 N / m.

In the present invention, after producing the double-sided pressure-sensitive adhesive layer-attached polarizing film 10, subsequently, after removing the separator SA ₁ from the adhesive layer A of the double-sided pressure-sensitive adhesive layer-attached polarizing film 10 obtained a separator SA _By sticking the curl adjusting separator SA ₁ ′ to the pressure-sensitive adhesive layer A of the double-sided pressure-sensitive adhesive film 13 having the ₁ peeled, a double-sided pressure-sensitive adhesive film 10 ′ can be produced. By using the curl adjusting separator SA ₁ ′ instead of the separator SA ₁ , the curl amount of the polarizing film 10 ′ with a double-sided pressure-sensitive adhesive layer can be adjusted. As shown in FIG. 7, it is preferable to perform the said manufacturing method by the process (2) bonded together by roll toe roll.

In Figure 7, delivery sided pressure-sensitive adhesive layer with the polarizing film 10 to be conveyed from the roll, by the peeling roll R6, are subjected to step (b) of separating the separator SA _1. Next, a step (2) in which the conveyed polarizing film 13 with a double-sided pressure-sensitive adhesive layer and the curling adjustment separator SA ₁ ′ are bonded between the pair of bonding rolls R4 and R5 is performed, and the winding roll Thus, a polarizing film 10 ′ with a double-sided pressure-sensitive adhesive layer is obtained.

The peel force a ₁ ′ of the curl adjusting separator SA ₁ ′ is preferably in the same range as the peel force a ₁ of the separator SA ₁ , and in relation to the peel force b of the separator SB, a ₁ ′> 1.5b is preferably satisfied from the viewpoint of curl amount adjustment.

Moreover, the double-sided pressure-sensitive adhesive layer-attached polarizing film 10 ′ of the present invention is a double-sided surface in which the tension T 3 of the curl adjusting separator SA ₁ ′ and the separator SA ₁ are separated in the step (2) of laminating with the roll-to-roll. It is preferable to control the ratio (T3 / T4) to the tension T4 of the polarizing film 13 with the pressure-sensitive adhesive layer to 0.8 or more. In FIG. 7, the tension T3 and the tension T4 can be controlled by rolls R13 and R14.

  The curl amount can be adjusted by controlling the tension ratio (T3 / T4) within the range. 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) becomes too large, the curl amount becomes too large, and the bonding accuracy is lowered in the bonding process to the panel. Therefore, the tension ratio (T3 / T4) is 10 or less. Preferably, it is 6 or less, more preferably 4 or less.

The tension T3 is preferably 8 to 500 N / m, more preferably 50 to 300 N / m, and even more preferably 100 to 200 N / m.
The tension T4 is preferably 10 to 400 N / m, more preferably 20 to 200 N / m, and further preferably 40 to 100 N / m.

  In addition, the magnitude | size of the said tension | tensile_strength can be adjusted with the torque etc. of a roll, The application method is not restrict | limited in particular, However, When sending a film etc. with a roll, tension | tensile_strength can be provided in the delivery direction. The tension can be measured by, for example, a load cell type tension pick-up roll that can be measured by a load applied to the transport roll. The tension is measured by the method described in Examples.

  The manufacturing method of the obtained polarizing film with a double-sided pressure-sensitive adhesive layer is subsequently a step (c) of cutting to an arbitrary size, and a step of cutting the edge of the cut polarizing film with a double-sided pressure-sensitive adhesive layer ( d) can be included. The cutting step (d) can include a polishing step.

<Material of adhesive layer>
Moreover, as a forming material of the adhesive layer A and the adhesive layer B of this invention, what contains various base polymers can be used. There are no particular restrictions on the type of base polymer, but examples include rubber polymers, (meth) acrylic polymers, silicone polymers, urethane polymers, vinyl alkyl ether polymers, polyvinyl alcohol polymers, polyvinyl pyrrolidone polymers, poly polymers. Various polymers such as acrylamide polymer and cellulose polymer are listed.

  Among these base polymers, those excellent in optical transparency, exhibiting appropriate wettability, cohesiveness, and adhesive pressure-sensitive adhesive properties and excellent in weather resistance and heat resistance are preferably used. A (meth) acrylic polymer is preferably used as such a feature. Hereinafter, an acrylic pressure-sensitive adhesive having a base polymer of a (meth) acrylic polymer containing alkyl (meth) acrylate as a monomer unit as a material for forming the pressure-sensitive adhesive layer A and the pressure-sensitive adhesive layer B will be described.

  The (meth) acrylic polymer can be 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 the ester group. Alkyl (meth) acrylate refers to alkyl acrylate and / or alkyl methacrylate, and (meth) in the present invention has the same meaning.

  Examples of the alkyl (meth) acrylate include those having a linear or branched alkyl group having 4 to 24 carbon atoms. Alkyl (meth) acrylate can be used individually by 1 type or in combination of 2 or more types.

  As said alkyl (meth) acrylate, the alkyl (meth) acrylate which has the said C4-C9 branch can be illustrated, for example. The alkyl (meth) acrylate is preferable in terms of easily balancing the adhesive properties. Examples of the alkyl (meth) acrylate include n-butyl (meth) acrylate, s-butyl (meth) acrylate, t-butyl (meth) acrylate, isobutyl (meth) acrylate, n-pentyl (meth) acrylate, and isopentyl ( Examples include meth) acrylate, isohexyl (meth) acrylate, isoheptyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isooctyl (meth) acrylate, and isononyl (meth) acrylate. In addition, the (meth) acrylic polymer according to the pressure-sensitive adhesive layer A preferably contains the largest amount of 2-ethylhexyl acrylate as a monomer unit from the standpoint of step absorbability 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), as a multiple pressure-sensitive adhesive layer (as a sum of each layer), The (meth) acrylic polymer preferably contains the most 2-ethylhexyl acrylate as a monomer unit. On the other hand, the (meth) acrylic polymer according to the pressure-sensitive adhesive layer B contains the most butyl acrylate as a monomer unit to control the storage elastic modulus, from the viewpoint of workability, storability and durability. preferable.

  In the present invention, the alkyl (meth) acrylate having an alkyl group having 4 to 24 carbon atoms at the ester end is 40% by weight or more based on the total amount of the monofunctional monomer component forming the (meth) acrylic polymer. It is preferably 50% by weight or more, more preferably 60% by weight or more. The use of 40% by weight or more is preferable from the viewpoint of easily balancing the adhesive properties.

  The monomer component forming the (meth) acrylic polymer of the present invention can contain a copolymerizable monomer other than the alkyl (meth) acrylate as a monofunctional monomer component. A copolymerization monomer can be used as the remainder of the said alkyl (meth) acrylate in a monomer component.

  As the copolymerization monomer, for example, a cyclic nitrogen-containing monomer can be included. 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 cyclic nitrogen-containing monomers include lactam vinyl monomers such as N-vinylpyrrolidone, N-vinyl-ε-caprolactam, and methylvinylpyrrolidone; vinylpyridine, vinylpiperidone, vinylpyrimidine, vinylpiperazine, vinylpyrazine, vinylpyrrole, and vinyl. Examples thereof include vinyl monomers having a nitrogen-containing heterocyclic ring such as imidazole, vinyl oxazole and vinyl morpholine. Moreover, the (meth) acryl monomer containing heterocyclic rings, such as a morpholine ring, a piperidine ring, a pyrrolidine ring, a piperazine ring, is mentioned. Specific examples include N-acryloylmorpholine, N-acryloylpiperidine, N-methacryloylpiperidine, N-acryloylpyrrolidine and the like. Among the cyclic nitrogen-containing monomers, lactam vinyl monomers are preferable from the viewpoint of dielectric constant and cohesiveness.

  In the present invention, the cyclic nitrogen-containing monomer is preferably 45% by weight or less, more preferably 0.5 to 40% by weight, and still more preferably based on all monomer components forming the (meth) acrylic polymer. 0.5 to 30% by weight. Use of the cyclic nitrogen-containing monomer in the above range is preferable in terms of control of the surface resistance value, particularly compatibility with the ionic compound when using the ionic compound, and durability of the antistatic function.

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

  As the hydroxyl group-containing monomer, 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 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 ( Hydroxyalkyl (meth) acrylates such as (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, 8-hydroxyoctyl (meth) acrylate, 10-hydroxydecyl (meth) acrylate, 12-hydroxylauryl (meth) acrylate and the like; And hydroxyalkylcycloalkane (meth) acrylates such as 4-hydroxymethylcyclohexyl) methyl (meth) acrylate. Other examples include hydroxyethyl (meth) acrylamide, allyl alcohol, 2-hydroxyethyl vinyl ether, 4-hydroxybutyl vinyl ether, diethylene glycol monovinyl ether, and the like. These can be used alone or in combination. Of these, hydroxyalkyl (meth) acrylate is preferred.

  As the carboxyl group-containing monomer, 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 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, and isocrotonic acid. Can be used alone or in combination. These anhydrides can be used for itaconic acid and maleic acid. Among these, acrylic acid and methacrylic acid are preferable, and acrylic acid is particularly preferable. In addition, a carboxyl group-containing monomer can be arbitrarily used for the monomer component used for manufacture of the (meth) acrylic-type polymer of this invention, On the other hand, it is not necessary to use a carboxyl group-containing monomer. A pressure-sensitive adhesive containing a (meth) acrylic polymer obtained from a monomer component not containing a 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 a cyclic ether group such as an epoxy group or an oxetane group. It can be used without particular limitation. Examples of the epoxy group-containing monomer include glycidyl (meth) acrylate, 3,4-epoxycyclohexylmethyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate glycidyl ether, and the like. Examples of the oxetane group-containing monomer include 3-oxetanylmethyl (meth) acrylate, 3-methyl-oxetanylmethyl (meth) acrylate, 3-ethyl-oxetanylmethyl (meth) acrylate, and 3-butyl-oxetanylmethyl (meth) acrylate. , 3-hexyl-oxetanylmethyl (meth) acrylate, and the like. These can be used alone or in combination.

  In the present invention, the hydroxyl group-containing monomer, the carboxyl group-containing monomer, and the monomer having a cyclic ether group are 30% by weight or less based on the total amount of the monofunctional monomer component forming the (meth) acrylic polymer. Further, it is preferably 27% by weight or less, more preferably 25% by weight or less.

The monomer component that forms the (meth) acrylic polymer of the present invention includes, for example, CH ₂ ═C (R ¹ ) COOR ² (wherein R ¹ is hydrogen or a methyl group, R ² is carbon number 1) as a copolymerization monomer. -3 represents an unsubstituted alkyl group or a substituted alkyl group or a cyclic cycloalkyl group).

Here, the unsubstituted alkyl group having 1 to 3 carbon atoms or the substituted alkyl group as R ² represents a linear or branched alkyl group. In the case of a 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 is preferably a phenyl group.

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

In the present invention, the (meth) acrylate represented by CH ₂ ═C (R ¹ ) COOR ² is 45% by weight or less based on the total amount of the monofunctional monomer component forming the (meth) acrylic polymer. It can be used and is preferably 35% by weight or less. Furthermore, 30 weight% or less is preferable.

  Other copolymer monomers include vinyl acetate, vinyl propionate, styrene, α-methylstyrene; (meth) acrylic acid polyethylene glycol, (meth) acrylic acid polypropylene glycol, (meth) acrylic acid methoxyethylene glycol, (meth) Glycol acrylic ester monomers such as methoxypolypropylene glycol acrylate; Acrylic ester monomers such as tetrahydrofurfuryl (meth) acrylate, fluorine (meth) acrylate, silicone (meth) acrylate and 2-methoxyethyl acrylate; Monomers, amino group-containing monomers, imide group-containing monomers, N-acryloylmorpholine, vinyl ether monomers and the like can also be used. Moreover, as a copolymerization monomer, the monomer which has cyclic structures, such as terpene (meth) acrylate and dicyclopentanyl (meth) acrylate, can be used.

  Furthermore, the silane type monomer containing a silicon atom, etc. are mentioned. Examples of the silane monomer include 3-acryloxypropyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, 4-vinylbutyltrimethoxysilane, 4-vinylbutyltriethoxysilane, and 8-vinyloctyltrimethoxysilane. , 8-vinyloctyltriethoxysilane, 10-methacryloyloxydecyltrimethoxysilane, 10-acryloyloxydecyltrimethoxysilane, 10-methacryloyloxydecyltriethoxysilane, 10-acryloyloxydecyltriethoxysilane, and the like.

  The copolymerization monomer can be appropriately selected when the pressure-sensitive adhesive layer A and the pressure-sensitive adhesive layer B are formed, when preparing the (meth) acrylic polymer as the base polymer. As the copolymerization monomer, in the case where the first pressure-sensitive adhesive layer (a) and the pressure-sensitive adhesive layer B in the pressure-sensitive adhesive layer A are formed of an acrylic pressure-sensitive adhesive, the cohesive force, the adhesive force improvement, the transparency, the durability From the viewpoint of properties, it is preferable that at least one of these includes at least one of (meth) acrylic acid and a nitrogen-containing monomer as a monomer unit.

  The monomer component that forms the (meth) acrylic polymer of the present invention contains a polyfunctional monomer as necessary in order to adjust the cohesive strength of the pressure-sensitive adhesive, in addition to the monofunctional monomer exemplified above. be able to.

  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, such as (poly) ethylene glycol di (meth) acrylate, (Poly) propylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, pentaerythritol di (meth) acrylate, pentaerythritol tri (meth) acrylate, propoxylated pentaerythritol triacrylate, dipentaerythritol hexa (meth) Acrylate, 1,2-ethylene glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, 1,12-dodecanediol di (meth) acrylate, trimethylolpropane tri (meth) acrylate Rate, ester compounds of polyhydric alcohols such as tetramethylolmethane tri (meth) acrylate and (meth) acrylic acid; allyl (meth) acrylate, vinyl (meth) acrylate, divinylbenzene, epoxy acrylate, polyester acrylate, urethane acrylate, Examples include butanediol di (meth) acrylate and hexanediol di (meth) acrylate. Among these, trimethylolpropane tri (meth) acrylate, hexanediol di (meth) acrylate, and dipentaerythritol hexa (meth) acrylate can be preferably used. A polyfunctional monomer can be used individually by 1 type or in combination of 2 or more types.

  The amount of the polyfunctional monomer used varies depending on the molecular weight, the number of functional groups, etc., but it is preferably used at 3 parts by weight or less, more preferably 2 parts by weight or less, with respect to 100 parts by weight of the monofunctional monomer in total. 1 part by weight or less is more preferable. Moreover, it does not specifically limit as a lower limit, However It is preferable that it is 0 weight part or more, and it is more preferable that it is 0.001 weight part or more. Adhesive force can be improved when the usage-amount of a polyfunctional monomer exists in the said range.

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

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

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

  Examples of the thermal polymerization initiator used for solution polymerization include 2,2′-azobisisobutyronitrile, 2,2′-azobis-2-methylbutyronitrile, 2,2′-azobis (2 -Methylpropionic acid) dimethyl, 4,4'-azobis-4-cyanovaleric acid, azobisisovaleronitrile, 2,2'-azobis (2-amidinopropane) dihydrochloride, 2,2'-azobis [2- (5-Methyl-2-imidazolin-2-yl) propane] dihydrochloride, 2,2′-azobis (2-methylpropionamidine) disulfate, 2,2′-azobis (N, N′-dimethyleneisobutyl) Amidine), 2,2′-azobis [N- (2-carboxyethyl) -2-methylpropionamidine] hydrate (manufactured by Wako Pure Chemical Industries, Ltd., VA-057) Any azo initiator, persulfate such as potassium persulfate, ammonium persulfate, di (2-ethylhexyl) peroxydicarbonate, di (4-t-butylcyclohexyl) peroxydicarbonate, di-sec-butylperoxy Dicarbonate, t-butylperoxyneodecanoate, t-hexylperoxypivalate, t-butylperoxypivalate, dilauroyl peroxide, di-n-octanoyl peroxide, 1,1,3,3 -Tetramethylbutylperoxy-2-ethylhexanoate, di (4-methylbenzoyl) peroxide, dibenzoyl peroxide, t-butylperoxyisobutyrate, 1,1-di (t-hexylperoxy) cyclohexane , Peracids such as t-butyl hydroperoxide and hydrogen peroxide Physical initiators, combinations of persulfates and sodium bisulfite, redox initiators combining peroxides and reducing agents, such as combinations of peroxides and sodium ascorbate, etc. It is not limited.

  The polymerization initiator may be used alone or in combination of two or more, but the total content is 0.005 to 1 part by weight with respect to 100 parts by weight of the monomer. Is preferably about 0.02 to 0.5 parts by weight.

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

  Examples of the chain transfer agent include lauryl mercaptan, glycidyl mercaptan, mercaptoacetic acid, 2-mercaptoethanol, thioglycolic acid, 2-ethylhexyl thioglycolate, and 2,3-dimercapto-1-propanol. The chain transfer agent may be used alone or in combination of two or more, but the total content is 0.1 parts by weight with respect to 100 parts by weight of the total amount of monomer components. Less than or equal to

  Examples of the emulsifier used for emulsion polymerization include anionic emulsifiers such as sodium lauryl sulfate, ammonium lauryl sulfate, sodium dodecylbenzenesulfonate, ammonium polyoxyethylene alkyl ether sulfate, sodium polyoxyethylene alkyl phenyl ether sulfate, and polyoxy Nonionic emulsifiers such as ethylene alkyl ether, polyoxyethylene alkyl phenyl ether, polyoxyethylene fatty acid ester, and polyoxyethylene-polyoxypropylene block polymer are exemplified. These emulsifiers may be used alone or in combination of two or more.

  Further, as reactive emulsifiers, as emulsifiers into which radical polymerizable functional groups such as propenyl groups and allyl ether groups are introduced, specifically, for example, Aqualon HS-10, HS-20, KH-10, BC-05 BC-10, BC-20 (all of which are manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), Adeka Soap SE10N (manufactured by ADEKA), and the like. Reactive emulsifiers are preferable because they are incorporated into the polymer chain after polymerization and thus have improved water resistance. The amount of the emulsifier used is more preferably 0.3 to 5 parts by weight and 0.5 to 1 part by weight from the viewpoint of polymerization stability and mechanical stability with respect to 100 parts by weight of the total amount of monomer components.

  Further, when the (meth) acrylic polymer is produced by active energy ray polymerization, the monomer component can be produced by polymerizing the monomer component by irradiating it with an active energy ray such as an electron beam or ultraviolet ray. When the active energy ray polymerization is performed with an electron beam, it is not particularly necessary that the monomer component contains a photopolymerization initiator, but when the active energy ray polymerization is performed with ultraviolet polymerization, in particular, From the advantage that the polymerization time can be shortened, the monomer component can contain a photopolymerization initiator. A photoinitiator can be used individually by 1 type or in combination of 2 or more types. As the monomer component, a part of the monomer component previously polymerized into a syrup can be used for irradiation.

  The photopolymerization initiator is not particularly limited, but is not particularly limited as long as it initiates photopolymerization, and a commonly used photopolymerization initiator can be used. For example, benzoin ether photopolymerization initiator, acetophenone photopolymerization initiator, α-ketol photopolymerization initiator, aromatic sulfonyl chloride photopolymerization initiator, photoactive oxime photopolymerization initiator, benzoin photopolymerization initiator Agents, benzyl photopolymerization initiators, benzophenone photopolymerization initiators, ketal photopolymerization initiators, thioxanthone photopolymerization initiators, acylphosphine oxide photopolymerization initiators, and the like can be used.

  Specifically, 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-diphenylethane- 1-one [trade name: Irgacure 651, manufactured by BASF Corporation], anisoin methyl ether and the like can be mentioned. Examples of the acetophenone photopolymerization initiator include 1-hydroxycyclohexyl phenyl ketone [trade name: Irgacure 184, manufactured by BASF], 4-phenoxydichloroacetophenone, 4-t-butyl-dichloroacetophenone, 1- [4- ( 2-hydroxyethoxy) -phenyl] -2-hydroxy-2-methyl-1-propan-1-one [trade name: Irgacure 2959, manufactured by BASF Corp.], 2-hydroxy-2-methyl-1-phenyl-propane- 1-one [trade name: Darocur 1173, manufactured by BASF Corporation], methoxyacetophenone, and the like can be given. Examples of the α-ketol photopolymerization initiator include 2-methyl-2-hydroxypropiophenone, 1- [4- (2-hydroxyethyl) -phenyl] -2-hydroxy-2-methylpropane-1- ON etc. are mentioned. Examples of the aromatic sulfonyl chloride photopolymerization initiator include 2-naphthalene sulfonyl chloride. Examples of the photoactive oxime photopolymerization initiator include 1-phenyl-1,2-propanedione-2- (O-ethoxycarbonyl) -oxime.

  The benzoin photopolymerization initiator includes, for example, benzoin. Examples of the benzyl photopolymerization initiator include benzyl. Examples of the benzophenone-based photopolymerization initiator include benzophenone, benzoylbenzoic acid, 3,3′-dimethyl-4-methoxybenzophenone, polyvinylbenzophenone, α-hydroxycyclohexyl phenyl ketone, and the like. Examples of the ketal photopolymerization initiator include benzyl dimethyl ketal. Examples of the thioxanthone photopolymerization initiator include thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, 2,4-dimethylthioxanthone, isopropylthioxanthone, 2,4-dichlorothioxanthone, 2,4-diethylthioxanthone, isopropylthioxanthone, 2,4-diisopropylthioxanthone, dodecylthioxanthone and the like are included.

  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-1-yl) phosphine oxide, bis (2,6-dimethoxybenzoyl)-(1 -Methylpropan-1-yl) phosphine oxide, bis (2,6-dimethoxybenzoyl) -t-butylphosphine oxide, bis (2,6-dimethoxybenzoyl) cyclohexylphosphine oxide, bis (2,6-dimethoxybenzoyl) octyl Phosphine oxide, bi (2-methoxybenzoyl) (2-methylpropan-1-yl) phosphine oxide, bis (2-methoxybenzoyl) (1-methylpropan-1-yl) phosphine oxide, bis (2,6-diethoxybenzoyl) ( 2-methylpropan-1-yl) phosphine oxide, bis (2,6-diethoxybenzoyl) (1-methylpropan-1-yl) phosphine oxide, bis (2,6-dibutoxybenzoyl) (2-methylpropane -1-yl) phosphine oxide, bis (2,4-dimethoxybenzoyl) (2-methylpropan-1-yl) phosphine oxide, bis (2,4,6-trimethylbenzoyl) (2,4-dipentoxyphenyl) ) Phosphine oxide, bis (2,6-dimethoxybenzoyl) benzylphosphineoxy Bis (2,6-dimethoxybenzoyl) -2-phenylpropylphosphine oxide, bis (2,6-dimethoxybenzoyl) -2-phenylethylphosphine oxide, bis (2,6-dimethoxybenzoyl) benzylphosphine oxide, bis ( 2,6-dimethoxybenzoyl) -2-phenylpropylphosphine oxide, bis (2,6-dimethoxybenzoyl) -2-phenylethylphosphine oxide, 2,6-dimethoxybenzoylbenzylbutylphosphine oxide, 2,6-dimethoxybenzoylbenzyl Octylphosphine oxide, bis (2,4,6-trimethylbenzoyl) -2,5-diisopropylphenylphosphine oxide, bis (2,4,6-trimethylbenzoyl) -2-methylphenylphosphine 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 oxide, 2,4,6-trimethylbenzoyldiphenyl Phosphine oxide, bis (2,6-dimethoxybenzoyl) -2,4,4-trimethylpentylphosphine oxide, bis (2,4,6-trimethylbenzoyl) isobutylphosphine oxide, 2,6-dimethoxybenzoyl-2,4 , 6-Trimethylbenzoyl-n-butylphosphine oxide, bis ( , 4,6-trimethylbenzoyl) phenylphosphine oxide, bis (2,4,6-trimethylbenzoyl) -2,4-dibutoxyphenylphosphine oxide, 1,10-bis [bis (2,4,6-trimethylbenzoyl) ) Phosphine oxide] decane, tri (2-methylbenzoyl) phosphine oxide, and the like.

  Although the usage-amount of a photoinitiator is not restrict | limited in particular, For example, 0.01-5 weight part with respect to 100 weight part of said monomer components, Preferably it is 0.05-3 weight part, More preferably, it is 0.05- The amount is 1.5 parts by weight, more preferably 0.1 to 1 part by weight.

  If the amount of the photopolymerization initiator used is less than 0.01 parts by weight, the polymerization reaction may be insufficient. When the usage-amount of a photoinitiator exceeds 5 weight part, a photoinitiator may absorb an ultraviolet-ray and an ultraviolet-ray may not reach the inside of an adhesive layer. In this case, the polymerization rate is lowered, or the molecular weight of the produced polymer is reduced. And thereby, the cohesive force of the pressure-sensitive adhesive layer to be formed becomes low, and when the pressure-sensitive adhesive layer is peeled off from the film, a part of the pressure-sensitive adhesive layer may remain on the film and the film may not be reused. . In addition, a photopolymerization initiator can be used individually by 1 type or in combination of 2 or more types.

  The weight average molecular weight of the (meth) acrylic polymer of the present invention is preferably 400,000 to 2,500,000, more preferably 600,000 to 2,200,000. By making the weight average molecular weight larger than 400,000, it is possible to satisfy the durability of the pressure-sensitive adhesive layer, or to suppress the occurrence of adhesive residue due to the reduced cohesive force of the pressure-sensitive adhesive layer. On the other hand, when the weight average molecular weight is larger than 2.5 million, the bonding property and the adhesive strength tend to be lowered. Furthermore, in the solution system, the viscosity becomes too high, and coating may be difficult. The weight average molecular weight is a value measured by GPC (gel permeation chromatography) and calculated in terms of polystyrene. In addition, it is difficult to measure the molecular weight of the (meth) acrylic polymer obtained by radiation polymerization.

<Measurement of weight average molecular weight>
The weight average molecular weight of the obtained (meth) acrylic polymer was measured by GPC (gel permeation chromatography). The sample used was a filtrate obtained by dissolving the sample in tetrahydrofuran to make a 0.1 wt% solution, which was allowed to stand overnight, and then filtered through a 0.45 μm membrane filter.
・ Analyzer: HLC-8120GPC manufactured by Tosoh Corporation
・ Column: Tosoh Corporation
(Meth) acrylic polymer: GM7000H _XL + GMH _XL + GMH _XL
Aromatic polymer: G3000HXL + 2000HXL + G1000HXL
・ Column size: 7.8mmφ × 30cm each 90cm in total
・ Eluent: Tetrahydrofuran (concentration 0.1% by weight)
・ Flow rate: 0.8ml / 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 forming the pressure-sensitive adhesive layer A and the pressure-sensitive adhesive layer B of the present invention can contain a crosslinking agent. Examples of crosslinking agents include isocyanate crosslinking agents, epoxy crosslinking agents, silicone crosslinking agents, oxazoline crosslinking agents, aziridine crosslinking agents, silane crosslinking agents, alkyletherified melamine crosslinking agents, metal chelate crosslinking agents, Crosslinkers such as oxides are included. A crosslinking agent can be used alone or in combination of two or more. As said crosslinking agent, an isocyanate type crosslinking agent and an epoxy-type crosslinking agent are used preferably.

  The crosslinking agent may be used alone or in combination of two or more, but the total content is based on 100 parts by weight of the (meth) acrylic polymer. It is preferable to contain the said crosslinking agent in 0.01-5 weight part. 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-based crosslinking agent refers to a compound having two or more isocyanate groups in a molecule (including isocyanate-regenerating functional groups in which isocyanate groups are temporarily protected by a blocking agent or quantification).

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

  More specifically, for example, lower aliphatic polyisocyanates such as butylene diisocyanate and hexamethylene diisocyanate, alicyclic isocyanates such as cyclopentylene diisocyanate, cyclohexylene diisocyanate and isophorone diisocyanate, 2,4-tolylene diisocyanate, Aromatic diisocyanates such as 4,4′-diphenylmethane diisocyanate, xylylene diisocyanate, polymethylene polyphenyl isocyanate, trimethylolpropane / tolylene diisocyanate trimer adduct (trade name Coronate L manufactured by Nippon Polyurethane Industry Co., Ltd.), tri Methylolpropane / hexamethylene diisocyanate trimer adduct (product name: Coronate HL, manufactured by Nippon Polyurethane Industry Co., Ltd.), hexamethylene diiso Isocyanurate of anate (product name: Coronate HX manufactured by Nippon Polyurethane Industry Co., Ltd.), trimethylolpropane adduct of xylylene diisocyanate (product name: D110N, manufactured by Mitsui Chemicals), trimethylolpropane of hexamethylene diisocyanate Additives (Mitsui Chemicals, trade name D160N); polyether polyisocyanates, polyester polyisocyanates, and adducts of these with various polyols, polyfunctionalized polyisocyanates, isocyanurate bonds, burette bonds, allophanate bonds, etc. An isocyanate etc. can be mentioned. Of these, it is preferable to use an aliphatic isocyanate because of its high reaction rate.

  The isocyanate-based crosslinking agent may be used alone or in combination of two or more, but the total content is 100 parts by weight of the (meth) acrylic polymer. On the other hand, it is preferable to contain 0.01-5 weight part of the said isocyanate type crosslinking agent, Furthermore, it is preferable to contain 0.01-4 weight part, Furthermore, it is preferable to contain 0.02-3 weight part. . It can be appropriately contained in consideration of cohesive force and prevention of peeling in a durability test.

  In addition, in the aqueous dispersion of the modified (meth) acrylic polymer prepared by emulsion polymerization, it is not necessary to use an isocyanate-based crosslinking agent. However, if necessary, it is blocked because it easily reacts with water. Isocyanate-based crosslinking agents can also be used.

  The said epoxy type crosslinking agent says the polyfunctional epoxy compound which has 2 or more of epoxy groups in 1 molecule. Examples of the epoxy crosslinking agent include bisphenol A, epichlorohydrin type epoxy resin, N, N, N ′, N′-tetraglycidyl-m-xylenediamine, diglycidylaniline, 1,3-bis (N, N -Diglycidylaminomethyl) cyclohexane, 1,6-hexanediol diglycidyl ether, neopentyl glycol diglycidyl ether, ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, sorbitol Polyglycidyl ether, glycerol polyglycidyl ether, pentaerythritol polyglycidyl ether, glycerin diglycidyl ether, glycerin triglycid Ether, polyglycerol polyglycidyl ether, sorbitan polyglycidyl ether, trimethylolpropane polyglycidyl ether, adipic acid diglycidyl ester, o-phthalic acid diglycidyl ester, triglycidyl-tris (2-hydroxyethyl) isocyanurate, resorcin diglycidyl In addition to ether and bisphenol-S-diglycidyl ether, there may be mentioned epoxy resins having two or more epoxy groups in the molecule. Examples of the epoxy-based crosslinking agent include commercially available products such as trade names “Tetrad C” and “Tetrad X” manufactured by Mitsubishi Gas Chemical Company.

  The epoxy crosslinking agent may be used alone or in combination of two or more. However, the total content is 100 parts by weight of the (meth) acrylic polymer. On the other hand, it is preferable to contain 0.01-5 weight part of the said epoxy type crosslinking agent, Furthermore, it is preferable to contain 0.01-4 weight part, Furthermore, it is preferable to contain 0.02-3 weight part. . It can be appropriately contained in consideration of cohesive force and prevention of peeling in a durability test.

  The peroxide crosslinking agent can be used as appropriate as long as it generates radical active species by heating to cause the crosslinking of the base polymer of the pressure-sensitive adhesive, but in consideration of workability and stability, 1 It is preferable to use a peroxide having a minute half-life temperature of 80 ° C to 160 ° C, and it is more preferable to use a peroxide having a temperature of 90 ° C to 140 ° C.

  Examples of peroxides that can be used include di (2-ethylhexyl) peroxydicarbonate (1 minute half-life temperature: 90.6 ° C.), di (4-t-butylcyclohexyl) peroxydicarbonate (1 Minute half-life temperature: 92.1 ° C.), di-sec-butyl peroxydicarbonate (1 minute half-life temperature: 92.4 ° C.), t-butyl peroxyneodecanoate (1 minute half-life temperature: 103 0.5 ° C), t-hexyl peroxypivalate (1 minute half-life temperature: 109.1 ° C), t-butyl peroxypivalate (1 minute half-life temperature: 110.3 ° C), dilauroyl peroxide ( 1 minute half-life temperature: 116.4 ° C.), di-n-octanoyl peroxide (1 minute half-life temperature: 117.4 ° C.), 1,1,3,3-tetramethylbutyl Oxy-2-ethylhexanoate (1 minute half-life temperature: 124.3 ° C), di (4-methylbenzoyl) peroxide (1 minute half-life temperature: 128.2 ° C), dibenzoyl peroxide (half-minute for 1 minute) Period temperature: 130.0 ° C.), t-butyl peroxyisobutyrate (1 minute half-life temperature: 136.1 ° C.), 1,1-di (t-hexylperoxy) cyclohexane (1 minute half-life temperature: 149.2 ° C.). Especially, since the crosslinking reaction efficiency is excellent, di (4-t-butylcyclohexyl) peroxydicarbonate (1 minute half-life temperature: 92.1 ° C.), dilauroyl peroxide (1 minute half-life temperature: 116. 4 ° C), dibenzoyl peroxide (1 minute half-life temperature: 130.0 ° C) and the like are preferably used.

  The peroxide half-life is an index representing the decomposition rate of the peroxide, and means the time until the remaining amount of peroxide is reduced to 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 catalog, for example, “Organic peroxide catalog 9th edition by Nippon Oil & Fats Co., Ltd.” (May 2003) ".

  The peroxide may be used alone or as a mixture of two or more, but the total content is based on 100 parts by weight of the (meth) acrylic polymer. The peroxide is 0.02 to 2 parts by weight, preferably 0.05 to 1 part by weight. In order to adjust processability, reworkability, cross-linking stability, peelability, and the like, it is appropriately selected within this range.

  In addition, as a measuring method of the peroxide decomposition amount which remained after the reaction process, it can measure by HPLC (high performance liquid chromatography), for example.

  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, and extracted by shaking at 25 ° C. and 120 rpm for 3 hours with a shaker. Let stand for days. Next, 10 ml of acetonitrile was added, shaken at 120 rpm at 25 ° C. for 30 minutes, and about 10 μl of the extract obtained by filtration through a membrane filter (0.45 μm) was injected into the HPLC for analysis. The amount of peroxide can be set.

  Moreover, you may use together an organic type crosslinking agent and a polyfunctional metal chelate as a crosslinking agent. A polyfunctional metal chelate is one in which a polyvalent metal is covalently or coordinately bonded to an organic compound. Examples of polyvalent metal atoms include Al, Cr, Zr, Co, Cu, Fe, Ni, V, Zn, In, Ca, Mg, Mn, Y, Ce, Sr, Ba, Mo, La, Sn, Ti, and the like. Can be mentioned. Examples of the atom in the organic compound that is covalently bonded or coordinated include an oxygen atom, and examples of the organic compound include an alkyl ester, an alcohol compound, a carboxylic acid compound, an ether compound, and a ketone compound.

  The pressure-sensitive adhesive forming the pressure-sensitive adhesive layer A and the pressure-sensitive adhesive layer B of the present invention can contain a polyfunctional monomer as a crosslinking agent. 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 is exemplified as a monomer component that forms a (meth) acrylic polymer. The thing similar to what was done can be illustrated.

  As the polyfunctional monomer as the crosslinking agent, one kind may be used alone, or two or more kinds may be mixed and used, but the content as a whole is the (meth) acrylic polymer 100 It is preferable to contain the said crosslinking agent (polyfunctional monomer) in 0.001-5 weight part with respect to weight part. The content of the crosslinking agent (polyfunctional monomer) is preferably 0.005 to 3 parts by weight, and more preferably 0.01 to 1 part by weight.

  A photopolymerization initiator is blended in the pressure-sensitive adhesive blended with the crosslinking agent (polyfunctional monomer). As a photoinitiator, the thing similar to what was used for preparing a (meth) acrylic-type polymer can be illustrated. The amount of the photopolymerization initiator used is usually 0.01 to 5 parts by weight, preferably 0.05 to 3 parts by weight, and more preferably 0.05 to 100 parts by weight of the crosslinking agent (polyfunctional monomer). It is -1.5 weight part, More preferably, it is 0.1-1 weight part. The pressure-sensitive adhesive containing the cross-linking agent (polyfunctional 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 according to the pressure-sensitive adhesive layer A can form a predetermined thickness such that at least one pressure-sensitive adhesive layer is an active energy ray-curable pressure-sensitive adhesive layer formed by irradiation with active energy rays. From the standpoint of step absorbability. In particular, the first pressure-sensitive adhesive layer (a) and / or the second pressure-sensitive adhesive layer (b) is preferably an active energy ray-curable pressure-sensitive adhesive layer.

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

  The (meth) acrylic oligomer preferably has a Tg of about 0 ° C. or higher and 300 ° C. or lower, preferably about 20 ° C. or higher and 300 ° C. or lower, more preferably about 40 ° C. or higher and 300 ° C. or lower. When the Tg is less than about 0 ° C., the cohesive force of the pressure-sensitive adhesive layer at room temperature or higher is lowered, and the holding characteristics and the adhesiveness at high temperature may be lowered. The Tg of the (meth) acrylic oligomer is a theoretical value calculated based on the Fox equation, similar to the Tg of the (meth) acrylic polymer.

  The weight average molecular weight of the (meth) acrylic oligomer is 1000 or more and less than 30000, preferably 1500 or more and less than 20000, and more preferably 2000 or more and less than 10,000. If the weight average molecular weight is 30000 or more, the effect of improving the adhesive strength may not be sufficiently obtained. On the other hand, if the molecular weight is less than 1000, the molecular weight may be low, which may cause a decrease in adhesive strength and retention characteristics. In this invention, the measurement of the weight average molecular weight of a (meth) acrylic-type oligomer can be calculated | required in polystyrene conversion by GPC method. Specifically, TSKgelGMH-H (20) × 2 columns are used in HPLC 8020 manufactured by Tosoh Corporation, and the measurement is performed with a tetrahydrofuran solvent at a flow rate of about 0.5 ml / min.

  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, and isobutyl (meth) acrylate. , S-butyl (meth) acrylate, t-butyl (meth) acrylate, pentyl (meth) acrylate, isopentyl (meth) acrylate, hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, heptyl (meth) acrylate, octyl (Meth) acrylate, isooctyl (meth) acrylate, nonyl (meth) acrylate, isononyl (meth) acrylate, decyl (meth) acrylate, isodecyl (meth) acrylate, undeci Alkyl (meth) acrylates such as (meth) acrylate and dodecyl (meth) acrylate; (meth) acrylic acid and alicyclic such as cyclohexyl (meth) acrylate, isobornyl (meth) acrylate and dicyclopentanyl (meth) acrylate An ester with a group alcohol; an aryl (meth) acrylate such as phenyl (meth) acrylate and benzyl (meth) acrylate; a (meth) acrylate obtained from a terpene compound derivative alcohol; and the like. Such (meth) acrylates can be used alone or in combination of two or more.

  Examples of (meth) acrylic oligomers include alkyl (meth) acrylates in which alkyl groups such as isobutyl (meth) acrylate and t-butyl (meth) acrylate have a branched structure; cyclohexyl (meth) acrylate and isobornyl (meth) Esters of (meth) acrylic acid and alicyclic alcohols such as acrylate and dicyclopentanyl (meth) acrylate; cyclic structures such as aryl (meth) acrylate such as phenyl (meth) acrylate and benzyl (meth) acrylate It is preferable that an acrylic monomer having a relatively bulky structure typified by (meth) acrylate having a monomer content is included as a monomer unit. By giving such a bulky structure to the (meth) acrylic oligomer, the adhesiveness of the pressure-sensitive adhesive layer can be further improved. In particular, those having a ring structure in terms of bulkiness are highly effective, and those having a plurality of rings are more effective. In addition, when ultraviolet rays are employed in the synthesis of a (meth) acrylic oligomer or in the production of a pressure-sensitive adhesive layer, those having a saturated bond are preferred in that they are less likely to cause polymerization inhibition. An alkyl (meth) acrylate having a branched structure or an ester with an alicyclic alcohol can be suitably used as a monomer constituting the (meth) acrylic oligomer.

  From this point, suitable (meth) acrylic oligomers include, for example, a copolymer of cyclohexyl methacrylate (CHMA) and isobutyl methacrylate (IBMA), and a copolymer of cyclohexyl methacrylate (CHMA) and isobornyl methacrylate (IBXMA). Polymer, copolymer of cyclohexyl methacrylate (CHMA) and acryloylmorpholine (ACMO), copolymer of cyclohexyl methacrylate (CHMA) and diethylacrylamide (DEAA), copolymer of 1-adamantyl acrylate (ADA) and methyl methacrylate (MMA) Polymer, copolymer of dicyclopentanyl methacrylate (DCPMA) and isobornyl methacrylate (IBXMA), cyclopentanyl methacrylate (DCPMA) and methyl Copolymer of acrylate (MMA), dicyclopentanyl methacrylate (DCPMA), cyclohexyl methacrylate (CHMA), isobornyl methacrylate (IBXMA), isobornyl acrylate (IBXA), dicyclopentanyl acrylate (DCPA), 1 -Adamantyl methacrylate (ADMA), 1-adamantyl acrylate (ADA) homopolymers, and the like. In particular, an oligomer containing CHMA as a main component is preferable.

  In the pressure-sensitive adhesive forming the pressure-sensitive adhesive layer A and pressure-sensitive adhesive layer B of the present invention, when the (meth) acrylic oligomer is used, the content thereof is not particularly limited, but is 100 parts by weight of the (meth) acrylic polymer. It is preferably 70 parts by weight or less, more preferably 1 to 70 parts by weight, further preferably 2 to 50 parts by weight, and further preferably 3 to 40 parts by weight. When the added amount of the (meth) acrylic oligomer exceeds 70 parts by weight, there is a problem that the elastic modulus is increased and the adhesiveness at low temperature is deteriorated. In addition, it is effective from the point of the improvement effect of adhesive force, when mix | blending 1 weight part or more of (meth) acrylic-type oligomers.

  Furthermore, the pressure-sensitive adhesive forming the pressure-sensitive adhesive layer A and pressure-sensitive adhesive layer B of the present invention includes a silane cup for increasing the water resistance at the interface when applied to a hydrophilic adherend such as glass of the pressure-sensitive adhesive layer. A ring agent can be contained. The amount of the silane coupling agent is preferably 1 part by weight or less, more preferably 0.01 to 1 part by weight, still more preferably 0.02 to 0 parts per 100 parts by weight of the (meth) acrylic polymer. .6 parts by weight. If the amount of the silane coupling agent is too large, the adhesion to the glass increases and the removability is poor, and if it is too small, the durability decreases, which is not preferable.

  Examples of silane coupling agents that can be preferably used include 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 2- (3,4-epoxy) Epoxy group-containing silane coupling agent such as cyclohexyl) ethyltrimethoxysilane, 3-aminopropyltrimethoxysilane, N-2- (aminoethyl) -3-aminopropylmethyldimethoxysilane, 3-triethoxysilyl-N- ( 1,3-dimethylbutylidene) propylamine, amino group-containing silane coupling agents such as N-phenyl-γ-aminopropyltrimethoxysilane, 3-acryloxypropyltrimethoxysilane, 3-methacryloxypropyltriethoxysilane, etc. (Meta) a Lil group-containing silane coupling agents, such as isocyanate group-containing silane coupling agents such as 3-isocyanate propyl triethoxysilane and the like.

  Furthermore, the pressure-sensitive adhesive forming the pressure-sensitive adhesive layer A and the pressure-sensitive adhesive layer B of the present invention may contain other known additives. For example, a polyether compound of polyalkylene glycol such as polypropylene glycol, coloring Powders, dyes, surfactants, plasticizers, tackifiers, surface lubricants, leveling agents, softeners, antioxidants, anti-aging agents, light stabilizers, UV absorbers, polymerization prohibited An agent, an inorganic or organic filler, a metal powder, a particulate shape, a foil-like material, and the like can be appropriately added depending on the use. Moreover, you may employ | adopt the redox system which added a reducing agent within the controllable range.

  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 substrate and / or a polarizing film and drying and removing the polymerization solvent. . In applying the forming material, one or more solvents other than the polymerization solvent may be added as appropriate.

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

  The heating and drying temperature is preferably 40 ° C to 200 ° C, more preferably 50 ° C to 180 ° C, and particularly preferably 70 ° C to 170 ° C. By making heating temperature into the said range, the adhesive layer A or the adhesive layer B which has the outstanding adhesion characteristic can be obtained. As the drying time, an appropriate time can be adopted as appropriate. The drying time is preferably 5 seconds to 20 minutes, more preferably 5 seconds to 10 minutes, and particularly preferably 10 seconds to 5 minutes.

  The pressure-sensitive adhesive layer A and the pressure-sensitive adhesive layer B are polymerized by irradiating active energy rays such as ultraviolet rays when the forming material (pressure-sensitive adhesive) is an active energy ray-curable pressure-sensitive adhesive. It can be carried out. For ultraviolet irradiation, a high pressure mercury lamp, a low pressure mercury lamp, a metal halide lamp, or the like can be used.

  The pressure-sensitive adhesive layer A and the pressure-sensitive adhesive layer B can be transferred to a polarizing film or the like after being formed on a support. As the support, for example, a release-treated sheet can be used. A silicone release liner is preferably used as the release-treated sheet. When the pressure-sensitive adhesive layer A is a multiple pressure-sensitive adhesive layer, a layer formed by sequentially forming the first pressure-sensitive adhesive layer (a), the second pressure-sensitive adhesive layer (b), etc. on the release-treated sheet. The first pressure-sensitive adhesive layer (a), the second pressure-sensitive adhesive layer (b), and the like may be bonded to the polarizing film, or the first pressure-sensitive adhesive layer (a) may be the outermost surface. Further, it can be bonded to the polarizing film sequentially.

The release-treated sheet 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 (separator). In practical use, the peeled sheet is peeled off.

  Examples of the constituent material of the separator include, for example, plastic films such as polyethylene, polypropylene, polyethylene terephthalate, and polyester films, porous materials such as paper, cloth, and nonwoven fabric, nets, foam sheets, metal foils, and laminates thereof. Although a thin leaf body etc. can be mentioned, a plastic film is used suitably from the point which is excellent in surface smoothness.

  The plastic film is not particularly limited as long as it can protect the pressure-sensitive adhesive layer A or the pressure-sensitive adhesive layer B. For example, polyethylene film, polypropylene film, polybutene film, polybutadiene film, polymethylpentene film, polychlorinated film Examples include vinyl film, vinyl chloride copolymer film, polyethylene terephthalate film, polybutylene terephthalate film, polyurethane film, and ethylene-vinyl acetate copolymer film.

  For the separator, the plastic film is used as a base film, and if necessary, mold release and antifouling treatment with a silicone-based, fluorine-based, long-chain alkyl-based or fatty acid amide-based release agent, silica powder, etc. Alternatively, an antistatic treatment such as a coating type, a kneading type, or a vapor deposition type can also be performed. In particular, the release properties from the pressure-sensitive adhesive layer A and the pressure-sensitive adhesive layer B can be further improved by appropriately performing a release treatment such as silicone treatment, long-chain alkyl treatment, and fluorine treatment on the surface of the separator.

Examples of the silicone release layer include addition reaction type silicone resins. For example, KS-774, KS-775, KS-778, KS-779H, KS-847H, KS-847T manufactured by Shin-Etsu Chemical Co., Ltd. TPR-6700, TPR-6710, TPR-6721 manufactured by Toshiba Silicone, Toray Dow Corning Examples thereof include SD7220 and SD7226. The coating amount of the silicone-based release layer (after drying) of 0.01 to 2 g / ^{m 2,} preferably from 0.01 to 1 g / ^{m 2,} still more preferably in the range of 0.01 to 0.5 g / ^{m 2} .

  The release layer is formed by, for example, applying the above-mentioned material on the oligomer prevention layer by a conventionally known coating method such as reverse gravure coating, bar coating, die coating, etc., and then usually performing heat treatment at about 120 to 200 ° C. It can be done by curing by applying. Moreover, you may use together heat processing and active energy ray irradiation, such as ultraviolet irradiation, as needed.

The thickness of the separator (including the release layer) is usually about 5 to 200 μm. Since the thickness of the separator is related to the peeling force, it is preferable to adopt a thickness corresponding to the separator. The thicknesses of the separators SA ₁ , SA ₁ ′, and SA ₂ are all preferably 30 μm or more, more preferably 40 μm or more, and further preferably 50 μm or more, from the viewpoint of peeling force and prevention of dents. Specifically, the thickness of the separators SA ₁ , SA ₁ ′, SA ₂ is preferably 40 to 130 μm, and more preferably 50 to 80 μm. The thickness of the separator SB is preferably 10 to 80 μm, preferably 20 to 50 μm, more preferably 30 to 50 μm, and further preferably 30 to 40 μm. In the configuration of the polarizing film with a double-sided pressure-sensitive adhesive layer, the thickness of the separator is a combination of the case where the thickness of the separator SA ₁ (SA ₁ ′) is 50 μm or more and the case where the thickness of the separator SB is 30 to 50 μm. It is particularly preferable from the viewpoint of peeling force and prevention of dents.

  In providing 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 subjected to an easy adhesion treatment. Examples of the easy adhesion treatment include corona treatment, plasma treatment, excimer treatment, hard coat treatment, and undercoat treatment. Moreover, you may perform an easily bonding process on the surface of an adhesive layer. In the polarizing film with an adhesive layer of the present invention, it is preferable from the viewpoint of suppressing foaming that the surface of the polarizing film on which the adhesive layer A is laminated is peeled off and the foaming is suppressed.

  Moreover, the polarizing film with an adhesive layer of this invention can be prepared so that either site | part may have an antistatic function. The antistatic function can be imparted to the polarizing film with the pressure-sensitive adhesive layer, for example, by containing an antistatic agent in the polarizing film or the pressure-sensitive adhesive layer, or by separately providing an antistatic layer.

  In the polarizing film with a pressure-sensitive adhesive layer of the present invention, the antistatic layer is disposed on the viewing side rather than the polarizing film provided on the most viewing side in the polarizing film used in an image display device (for example, a liquid crystal display device). Can do. Therefore, there are problems such as depolarization that may occur when an antistatic layer (low surface resistance layer) is provided between the polarizing film on the viewing side and the liquid crystal panel, and deterioration of optical properties such as generation of bright spots due to impurities. It can be greatly reduced, and the reliability of the polarizing film provided on the most visible side is not impaired. Thus, an antistatic function can be imparted without impairing the performance of the image display apparatus.

  In particular, the present invention is effective when applied to a liquid crystal display device with a built-in touch sensor such as an in-cell type or an on-cell type, and the quality of the liquid crystal display device with a built-in touch sensor such as an in-cell type or an on-cell type can be improved.

  In order to impart an antistatic function to the pressure-sensitive adhesive forming the pressure-sensitive adhesive layer A and pressure-sensitive adhesive layer B of the present invention, an ionic compound can 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-anion salt can be preferably used. As the alkali metal salt, an organic salt or inorganic salt of an alkali metal can be used. The “organic cation-anion salt” in the present invention refers to an organic salt whose cation part is composed of an organic substance, and the anion part may be an organic substance or an inorganic substance. There may be. “Organic cation-anion salt” is also called an ionic liquid or 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 alkali metal salts and organic cation-anion salts. . These ionic compounds can be used alone or in combination.

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

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

<Creation of polarizing film>
A polyvinyl alcohol film having a thickness of 80 μm was stretched up to 3 times while being dyed for 1 minute in an iodine solution of 0.3% concentration at 30 ° C. between rolls having different speed ratios. Thereafter, the total draw ratio was stretched to 6 times while being immersed in an aqueous solution containing 60% at 4% concentration of boric acid and 10% concentration of potassium iodide for 0.5 minutes. Next, after washing by immersing in an aqueous solution containing potassium iodide at 30 ° C. and 1.5% concentration for 10 seconds, drying was performed at 50 ° C. for 4 minutes to obtain a polarizer having a thickness of 20 μm. A polarizing film was prepared by laminating a saponified 40 μm thick triacetyl cellulose film on one side of the polarizer and an acrylic film having a thickness of 20 μm on the other side with a polyvinyl alcohol adhesive. . The surface (triacetyl cellulose film side) on which the pressure-sensitive adhesive layer B of the polarizing film is bonded was appropriately subjected to corona treatment.

<Separator _SA 1>
A release film provided with the following release layer on a polyethylene terephthalate film having a thickness of 38 μm, 50 μm or 75 μm was used.

<Separator SA ₁ '>
A release film provided with the following release layer on a polyethylene terephthalate film having a thickness of 50 μm was used.

<Separator SA ₂ >
A release film provided with the following release layer on a polyethylene terephthalate film having a thickness of 50 μm was used.

<Separator SB>
A release film provided with the following release layer on a polyethylene terephthalate film having a thickness of 38 μm, 50 μm or 75 μm was used.

≪Formation of release layer≫
The following release layers were formed on each separator.
Silicone resin (KS-847H: manufactured by Shin-Etsu Chemical): 20 parts by weight and curing agent (PL-50T: manufactured by Shin-Etsu Chemical): 0.2 parts by weight of methyl ethyl ketone / toluene mixed solvent (mixing ratio is 1: 1) 350 weights The solution was diluted with a portion to prepare a silicone release agent solution. The silicone release agent solution was applied to each polyethylene terephthalate film (base film) with a gravure coater so that the thickness after drying was 100 nm, and then dried at 120 ° C. to form a release layer. The separator which formed and had the structure of a base film / release layer was obtained.

Production Example 1
<Preparation of forming material of adhesive layer A>
In a four-necked flask equipped with a stirring blade, thermometer, nitrogen gas inlet tube, and condenser, 70 parts of 2-ethylhexyl acrylate (2EHA), 15 parts of N-vinylpyrrolidone (NVP), 4-hydroxybutyl acrylate (4HBA) 15 parts, 2 types of photopolymerization initiator (trade name: Irgacure 184, manufactured by BASF) 0.05 part and photopolymerization initiator (trade name: Irgacure 651, manufactured by BASF) 0.05 part flask Was added to prepare a monomer mixture. Next, the monomer mixture was partially photopolymerized by exposure to ultraviolet rays under a nitrogen atmosphere, thereby obtaining a partially polymerized product (acrylic polymer syrup) having a polymerization rate of about 10%.

  Next, after adding 0.01 parts of trimethylolpropane triacrylate (TMPTA) to 100 parts of the acrylic polymer syrup described above, they are uniformly mixed to form a material for forming the adhesive layer A (monomer component: A1 ) Was prepared.

Production Examples 2-5
In Production Example 1, the same operation as in Production Example 1 was carried out except that the composition of each component used for the preparation of the monomer component was changed as shown in Table 1, and the material for forming the adhesive layer A (monomer component: A2 to A5) were prepared.

表１中、２ＥＨＡは、２−エチルヘキシルアクリレート；
ＮＶＰは、Ｎ−ビニルピロリドン；
４ＨＢＡは、４−ヒドロキシブチルアクリレート；
ＴＭＰＴＡは、トリメチロールプロパントリアクリレート；を示す。

In Table 1, 2EHA is 2-ethylhexyl acrylate;
NVP is N-vinylpyrrolidone;
4HBA is 4-hydroxybutyl acrylate;
TMPTA indicates trimethylolpropane triacrylate.

<Creation of adhesive layer A with separators on both sides>
The formation material (monomer component) of the pressure-sensitive adhesive layer A prepared in the above production example has a final thickness of 50 μm, 100 μm, 200 μm or 300 μm on the release treatment surface of the separator SA ₁ shown in Table 2 or Table 3. Was applied to form a coating layer. Then, the coated surface of the monomer component, the separator SA ₂ shown in Table 2 or Table 3 was release-treated surface of the film is coated in such a manner that the coating layer side. Thereby, the coating layer of the monomer component was shielded from oxygen. Using a chemical light lamp (manufactured by Toshiba Corporation) on the sheet having the coating layer thus obtained, ultraviolet rays having an illuminance of 5 mW / cm ² (measured with Topcon UVR-T1 having a maximum sensitivity at about 350 nm) are applied for 360 seconds. Irradiation was performed to cure the coating layer to form the pressure-sensitive adhesive layer A, thereby preparing a pressure-sensitive adhesive layer A with a separator on both sides.

<Preparation of pressure-sensitive adhesive forming pressure-sensitive adhesive layer B>
In a separable flask equipped with a thermometer, stirrer, reflux condenser and nitrogen gas inlet tube, 99 parts of butyl acrylate (BA), 1 part of 4-hydroxybutyl acrylate (4HBA) as monomer components, and azobis as a polymerization initiator After 0.2 parts of isobutyronitrile and ethyl acetate as a polymerization solvent were added so as to have a solid content of 30%, nitrogen substitution was performed for about 1 hour while flowing nitrogen gas and stirring. Thereafter, the flask was heated to 60 ° C. and reacted for 7 hours to obtain an acrylic polymer having a weight average molecular weight (Mw) of 1.1 million. To the acrylic polymer solution (solid content: 100 parts), 0.1 part of trimethylolpropan xylylene diisocyanate (Mitsui Chemical Co., Ltd., “Takenate D110N”) as an isocyanate crosslinking agent, silane coupling agent (Shin-Etsu Chemical ( 0.1 parts of “KBM-403” (manufactured by Co., Ltd.) was added to prepare an adhesive composition (solution).

<Creation of pressure-sensitive adhesive layer B with a separator>
The prepared pressure-sensitive adhesive solution was applied to the release-treated surface of the separator SB shown in Table 2 or Table 3 so that the thickness after drying was 20 μm. Under normal pressure, 3 minutes at 60 ° C. and 3 ° C. at 120 ° C. Heat-dried for 30 minutes, and further aged at 23 ° C. for 120 hours to prepare a pressure-sensitive adhesive layer B.

<Creation of polarizing film with one side adhesive layer B>
The pressure-sensitive adhesive layer B with the separator SB was transferred to one side (triacetylcellulose film side) of the polarizing film to prepare a polarizing film with the one-side pressure-sensitive adhesive layer B.

Example 1
<Creation of polarizing film with double-sided pressure-sensitive adhesive layer>
An apparatus as shown in FIG. 6 was used.
The two side separator pressure-sensitive adhesive layer A, conveys the feed roll, by the peeling roll and peeling the separator SA _2, and conveys the adhesive layer A of the separator with SA _1. On the other hand, separately, feeding the side of the polarizing film side adhesive layer B Tsukehen light film conveyed from the roll (acrylic film side), the pressure-sensitive adhesive layer A dated the separator SA _1, bonded by a pair of rolls A polarizing film with a double-sided pressure-sensitive adhesive layer was prepared by roll-to-roll. In addition, the bonding was performed while controlling the tension T1 of the one-side separator-attached pressure-sensitive adhesive layer A and the tension T2 of the one-side pressure-sensitive adhesive layer-B-attached polarizing film as shown in Table 2.

In the creation of the double-sided pressure-sensitive adhesive layer-attached polarizing film, a separator SA _1, separator SA _2, the thickness of the separator SB, peel force _{a 1} of the separator SA _1, peel strength _{a 2} separators SA _2, peel strength b of the separator SB is As shown in Table 1.
The surface on which the pressure-sensitive adhesive layer B of the polarizing film was bonded (triacetyl cellulose film side) was subjected to corona treatment.
The thickness of the pressure-sensitive adhesive layer A is as shown in Table 1.

<Measurement of tension>
The stress converted into 1 m width was measured using the roll for detection provided with Nireco MB tension sensor.

Examples 2 to 13 and Comparative Examples 1 to 5
In Example 1, the thickness of the separator SA ₁ , the separator SA ₂ , the separator SB,
Peel force _{a 1} of the separator SA _1, peel strength _{a 2} separators SA _2, the release 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 (type of pressure-sensitive adhesive),
Presence or absence of corona treatment on the surface to which the adhesive layer A of the polarizing film is bonded,
A double-sided pressure-sensitive adhesive layer was prepared in the same manner as in Example 1 except that the tension T1 of the pressure-sensitive adhesive layer A with one side separator and the tension T2 of the polarizing film with the single-sided pressure-sensitive adhesive layer B were changed as shown in Table 1. A polarizing film was prepared.
For Comparative Examples 1 and 2, not a roll-to-roll, but a polarizing film with a one-sided adhesive layer B and an adhesive layer A with a separator SA ₁ prepared for each, a sheet-fed film laminating device manufactured by Suntech Co., Ltd. And the absorption axis was a long side, and bonded together with an area of 500 mm × 400 mm.

Example 14
<Creation of polarizing film with double-sided pressure-sensitive adhesive layer>
An apparatus as shown in FIG. 7 was used.
Obtained in Comparative Example 3, the polarizing film with double-sided pressure-sensitive adhesive layer, while conveying the feed roll, by the peeling roll and peeling the separator SA _1, wherein the separator SA ₁ sided pressure-sensitive adhesive layer with polarized light separation The film was conveyed.
On the other hand, the curling adjustment separator SA ₁ ′ separately conveyed from the feeding roll is bonded to the pressure-sensitive adhesive layer A of the polarizing film with a double-sided pressure-sensitive adhesive layer by a pair of rolls, and the double-sided pressure-sensitive adhesive is roll-to-roll. A polarizing film with a layer was prepared. Further, the bonding is performed while controlling the tension T3 of the curl adjusting separator SA ₁ ′ and the tension T4 of the polarizing film with the double-sided pressure-sensitive adhesive layer from which the separator SA ₁ has been peeled as shown in Table 3. It was.

In the above polarizing film with double-sided pressure-sensitive adhesive layer, _'the thickness of the separator SA _1' separator SA 1 peel force a ₁ of _'are shown in the description of Table 3.

Comparative Example 6
In Example 14, a polarizing film with a double-sided pressure-sensitive adhesive layer transported from a feed roll (Comparative Example 3 is changed to Example 2), the tension T3 of the curl adjusting separator SA ₁ ′ and the both surfaces where the separator SA ₁ is peeled off A polarizing film with a double-sided pressure-sensitive adhesive layer was prepared in the same manner as in Example 14 except that the tension T4 of the polarizing film with a pressure-sensitive adhesive layer was changed as shown in Table 3.

  The following evaluation was performed about the polarizing film with a double-sided adhesive layer obtained by the said manufacture example, an Example, and the comparative example. The evaluation results are shown in Table 1.

<Measurement of shear storage modulus>
The shear storage modulus at 23 ° C. was determined by dynamic viscoelasticity measurement. The measurement sample (adhesive layer A, adhesive layer B) was subjected to a dynamic viscoelasticity measuring apparatus (apparatus name “ARES”, manufactured by TA Instruments Inc.) at a frequency of 1 Hz. The shear storage modulus at 23 ° C. was calculated by measuring at a temperature range of −20 to 100 ° C. and a heating rate of 5 ° C./min.

<Measurement of peel strength of separator>
A measurement sample with a separator (release liner) (adhesive layer A with separator, adhesive layer B with separator) is cut into a width of 50 mm and a length of 100 mm, and then the separator (release liner) is pulled from the sample with a tensile tester. The peeling force (N / 50 mm) when peeling at a peeling angle of 180 ° and a peeling speed of 300 mm / min was measured.

<Curl>
The polarizing film with a double-sided pressure-sensitive adhesive layer is placed on a horizontal plane so that the curled surface of the rectangular film is 300 mm in the absorption axis direction of the polarizing film and 250 mm in the direction perpendicular to the absorption axis. The distance (mm) of the longest point from the horizontal plane among the four corners was measured.

<Yield>
About the polarizing film with a double-sided pressure-sensitive adhesive layer (size is 70 mm × 100 mm), after separating the separator SB, the side of the pressure-sensitive adhesive layer B was bonded to a non-alkali glass (Corning Corp., 1737) with a thickness of 0.7 mm. . This operation was performed 10 times.
Then, in the bonding operation, it was confirmed whether or not the bonding operation could be completed without generating bubbles at the ends. The ratio (success rate) in the case where no bubbles are caught at the end is shown by the following criteria.
A: Success rate 100%.
A: Success rate of 80 to less than 100%.
Δ: Success rate 50 to less than 80%.
X: Success rate is less than 50%.

<Evaluation method of step absorbency>
A sheet piece having a width of 50 mm and a length of 100 mm was cut out from the adhesive layer A with a separator on both sides. One release film was peeled from the sheet piece, and the pressure-sensitive adhesive layer side of the sheet piece was bonded to a COP (cyclic polyolefin) film (thickness: 100 μm) using a hand roller.
Next, the other release film was peeled from the sheet piece bonded to the COP film. The glass plate with printing steps was bonded under the following bonding conditions so that the surface of the glass plate on which the printing steps were applied and the pressure-sensitive adhesive layer on the COP film were in contact. And the sample for evaluation which has a structure of a COP film / adhesive layer / glass plate with a printing level | step difference was obtained.
(Bonding conditions)
Surface pressure: 0.3 MPa
Pasting speed: 25mm / s
Roll rubber hardness: 70 °
In addition, the said glass plate with a printing level | step difference is the thickness (the height of a printing level | step difference) on one surface of a glass plate (Matsunami Glass Industrial Co., Ltd. product, length 100mm, width 50mm, thickness 0.7mm). ) Was a glass plate on which printing of 50 μm or 80 μm was applied.
(Step / thickness of the pressure-sensitive adhesive layer) × 100 (%), which is an index indicating the step absorbability, is 50% and 80%, respectively.
Next, the sample for evaluation was put into an autoclave, and autoclaved for 15 minutes under conditions of a pressure of 5 atm and a temperature of 50 ° C. After the autoclave treatment, a sample for evaluation was taken out, the state of sticking between the pressure-sensitive adhesive layer and the printed stepped glass plate was visually observed, and the step absorbability was evaluated according to the following evaluation criteria.
○: No bubbles remained and no float occurred between the pressure-sensitive adhesive layer and the printed stepped glass plate.
X: Air bubbles remain, and floating is generated between the pressure-sensitive adhesive layer and the printed stepped glass plate.

<Durability>
The separator film of the pressure-sensitive adhesive layer A (viewing side) of the polarizing film with the pressure-sensitive adhesive layer obtained in each of the above examples is peeled off and pasted to a non-alkali glass (Corning Corp., 1737) with a thickness of 0.7 mm using a laminator. I wore it. Subsequently, the autoclave process for 15 minutes was performed at 50 degreeC and 0.5 MPa, and the said polarizing film with an adhesive layer was completely stuck to the alkali free glass. Next, vacuum bonding was performed using a vacuum bonding apparatus manufactured by LANTECH under a pressure of 0.2 MPa and a degree of vacuum of 30 Pa. This was put into the conditions of a heating oven (heating) at 85 ° C. and 95 ° C. and a constant temperature and humidity machine (humidification) at 60 ° C./95% RH, and whether or not the polarizing film peeled after 500 hours, Evaluation was made according to the following criteria.
A: No peeling was observed.
○: Peeling that was not visually confirmed was observed.
(Triangle | delta): The small peeling which can be confirmed visually is recognized.
X: Clear peeling (over 0.5 μm) was observed.

比較例５の歩留まりの結果「気泡有」は、粘着剤層Ａの貯蔵弾性率が高いため、カバーガラスを貼り合せた後、カバーガラスのインク段差を埋めきれずに貼り合せ直後に気泡が発生していることを示す。

As a result of the yield of Comparative Example 5, “With bubbles”, since the storage elastic modulus of the adhesive layer A is high, bubbles are generated immediately after bonding without covering the ink step of the cover glass after bonding the cover glass. Indicates that

比較例６は、貼り代えにより、特定が低下した場合である。

The comparative example 6 is a case where specification falls by pasting.

1 Polarizing film A Adhesive layer A (viewing side)
B Adhesive layer B (opposite side of viewing side)
C member (touch panel or transparent substrate)
D Display unit (image display device)
SA ₁ separator for adhesive layer A (viewing side) SA ₁ ′ separator for curl adjustment of adhesive layer A (viewing side) SA ₂ separator for adhesive layer A (viewing side) SB adhesive layer B (opposite to viewing side) Side) separator 10, 10 'polarizing film with double-sided pressure-sensitive adhesive layer 11 pressure-sensitive adhesive layer A with single-sided separator
12 Polarizing film with one-sided adhesive layer B 13 Polarizing film with double-sided adhesive layer from which separator SA ₁ has been peeled 14 Adhesive layer A with double-sided separator
2 Adhesive layer (Adhesive layer B)
3 Transparent conductive layer (antistatic layer)
4 glass substrate 5 liquid crystal layer 6 drive electrode 7 antistatic layer / sensor layer 8 drive electrode / sensor layer 9 sensor layer a first adhesive layer b second adhesive layer

Claims (12)

In the polarizing film used for the image display device, a polarizing film provided on the most visible side, an adhesive layer A disposed on the viewing side of the polarizing film, and an adhesive layer B disposed on the opposite side of the adhesive layer A And a polarizing film with a double-sided pressure-sensitive adhesive layer comprising a separator SA _{1 in} the pressure-sensitive adhesive layer A and a separator SB in the pressure-sensitive adhesive layer B,
The pressure-sensitive adhesive layer A has a storage elastic modulus at 23 ° C. of 0.02 to 0.3 MPa,
The polarizing film with a double-sided pressure-sensitive adhesive layer is such that a curled convex surface is on the lower side of a rectangular object that is 300 mm in the absorption axis direction of the polarizing film and 250 mm in the direction perpendicular to the absorption axis. amount curl was measured by placing on a horizontal surface (however, the curl amount measured by placing on a horizontal surface so that the side becomes below the separator SB +, a horizontal plane so that the side of the separator SA ₁ on the lower side A polarizing film with a double-sided pressure-sensitive adhesive layer, wherein the curl amount measured by placing it on the surface is expressed as-, and is -10 mm to +60 mm.   The polarizing film with a double-sided pressure-sensitive adhesive layer according to claim 1, wherein the curl amount is +2 mm to +30 mm. The separator SA ₁ is a thickness of 50μm or more, the separator SB polarizing film double-sided pressure-sensitive adhesive layer according to claim 1 or 2, wherein the thickness of 30～55Myuemu. The peel force a ₁ of the separator SA ₁ is attached polarizing film sided pressure-sensitive adhesive layer according to any one of claims 1 to 3, wherein the higher peel strength b of the separator SB. It is a manufacturing method of the polarizing film with a double-sided adhesive layer in any one of Claims 1-4,
A polarizing film with a one-side pressure-sensitive adhesive layer B having a polarizing film and a pressure-sensitive adhesive layer B provided on the most visible side in a polarizing film used for an image display device, and having a separator SB in the pressure-sensitive adhesive layer B;
A pressure-sensitive adhesive layer A with a one-side separator having a pressure-sensitive adhesive layer A having a storage elastic modulus at 23 ° C. of 0.02 to 0.3 MPa on the separator SA ₁
Roll toe so that the pressure-sensitive adhesive layer A of the pressure-sensitive adhesive layer A with the one-side separator is disposed on the polarizing film on the side opposite to the side where the pressure-sensitive adhesive layer B is provided in the polarizing film with the one-side pressure-sensitive adhesive layer B. The manufacturing method of the polarizing film with a double-sided adhesive layer characterized by including the process (1) bonded together with a roll. The one-side separator-attached pressure-sensitive adhesive layer A is a step of separating the separator SA ₂ from the double-side separator-use pressure-sensitive adhesive layer A having the separator SA ₁ on one side of the pressure-sensitive adhesive layer A and the separator SA ₂ on the other side (a )
Claims wherein the peel force _{a 1} of the separator SA _1, peel strength _{a 2} of the separator SA _2, and peel strength b of the separator SB _is characterized by satisfying the a 1> _{a 2} ≧ b, the relationship The manufacturing method of the polarizing film with a double-sided adhesive layer of 5. Wherein the peel force _{a 1} of the separator SA _1, peel strength _{a 2} of the separator SA _2, and peel strength b of the separator SB _is, satisfies a 1> 1.5a ₂ ≧ 1.5b, the relationship The manufacturing method of the polarizing film with a double-sided adhesive layer of Claim 6. In the step (1) of laminating with the roll-to-roll,
8. The ratio (T1 / T2) of the tension T1 of the one-side separator-attached pressure-sensitive adhesive layer A and the tension T2 of the one-side pressure-sensitive adhesive layer-B polarizing film is controlled to be 0.8 or more. The manufacturing method of the polarizing film with a double-sided adhesive layer in any one. Following the method for producing a polarizing film with a double-sided pressure-sensitive adhesive layer according to any one of claims 5 to 7,
Step from the obtained polarizing film double-sided pressure-sensitive adhesive layer is peeled off the separator SA ₁ (b), and,
6. A step (2) of bonding a curl adjusting separator SA ₁ ′ by roll-to-roll to the pressure-sensitive adhesive layer A of the polarizing film with a double-sided pressure-sensitive adhesive layer from which the separator SA ₁ has been peeled off. The manufacturing method of the polarizing film with a double-sided adhesive layer in any one of -7. In the step (2) of laminating with the roll-to-roll,
The ratio (T3 / T4) between the tension T3 of the curl adjusting separator SA ₁ ′ and the tension T4 of the polarizing film with a double-sided pressure-sensitive adhesive layer from which the separator SA ₁ has been peeled is controlled to 0.8 or more. The manufacturing method of the polarizing film with an adhesive layer of Claim 9 to do. Following the method for producing a polarizing film with a double-sided pressure-sensitive adhesive layer according to any one of claims 5 to 10,
It includes a step (c) of cutting the obtained polarizing film with a double-sided pressure-sensitive adhesive layer into an arbitrary size, and a step (d) of cutting an end of the cut polarizing film with a double-sided pressure-sensitive adhesive layer. The manufacturing method of the polarizing film with a double-sided adhesive layer in any one of Claims 5-10 to do. An image display device having at least one polarizing film with a double-sided pressure-sensitive adhesive layer,
The polarizing film with a double-sided pressure-sensitive adhesive layer provided on the most visible side in the polarizing film used in the image display device is the separator SA ₁ and the separator from the polarizing film with a double-sided pressure-sensitive adhesive layer according to claim 1. SB is removed,
The image display apparatus, wherein the pressure-sensitive adhesive layer A of the polarizing film with a double-sided pressure-sensitive adhesive layer is disposed on the viewing side, and the pressure-sensitive adhesive layer B is on the display unit side.

Images