CN116075567A - Method for producing adhesive sheet product - Google Patents

Abstract

The method for producing an adhesive sheet adhesive article of the present invention comprises a step of adhering an adhesive sheet (S) to an adherend. The adhesive layer (10) of the adhesive sheet (S) is capable of being discolored and cured by irradiation of the 1 st active ray and is capable of being cured by irradiation of the 2 nd active ray. The method comprises the following steps: a step of curing the adhesive layer (10) by irradiation of the 2 nd active ray; and a step of forming a color change portion in the adhesive layer (10) by irradiating at least a part of the adhesive layer (10) with the 1 st active light; or comprises the following steps: a step of changing color and curing the adhesive layer (10) by irradiation of the 1 st active light, or a step of: a step of changing the color and curing the 1 st part of the adhesive layer (10) by irradiation of the 1 st active light; and a step of curing the 2 nd part of the adhesive layer (10) by irradiation of the 2 nd active light.

Description

Method for producing adhesive sheet product

Technical Field

The present invention relates to a method for producing an adhesive sheet product.

Background

Display panels such as organic EL panels have a laminated structure including a pixel panel and a protective member. In the manufacturing process of such a display panel, for example, a transparent adhesive sheet is used for bonding elements included in the laminated structure to each other.

As a transparent adhesive sheet to be disposed on the light emission side (image display side) of a pixel panel in a display panel, an adhesive sheet in which a colored portion for imparting design, shielding, antireflection, and the like to a predetermined portion of the same sheet is formed in advance has been proposed. Such an adhesive sheet is described in patent document 1, for example. Specifically, patent document 1 describes an adhesive sheet having a colored portion containing a carbon black pigment.

Prior art literature

Patent literature

Patent document 1: japanese patent application laid-open No. 2017-203810

Disclosure of Invention

Problems to be solved by the invention

However, in the case of using an adhesive sheet having a colored portion formed in advance in the process of manufacturing an article such as a display panel, it is not possible to appropriately check the presence or absence of foreign matter and air bubbles between the adherend and the colored portion of the adhesive sheet after the adhesive sheet is bonded to the adherend. In the bonding of an adhesive sheet in the process of producing an article, it is required that the presence or absence of foreign matter and air bubbles between an adherend and the adhesive sheet after the bonding can be appropriately checked.

On the other hand, for example, from the viewpoint of ensuring the function of a colored portion (color change portion) of a transparent adhesive sheet for a display panel, it is required that deterioration of the colored portion be suppressed. The deterioration of the colored portion may be, for example, deformation of the colored portion due to deformation of the adhesive layer. Examples of the deterioration of the color change portion include bleeding, fading, and unevenness in color appearance of the colored portion due to diffusion of the coloring component contained in the colored portion.

The present invention provides: a method for producing an adhesive sheet adhesive article, which can discolor at least a part of an adhesive sheet bonded to an adherend and which is suitable for suppressing deterioration of the discolored part.

Solution for solving the problem

The present invention [1] includes a method for producing an adhesive sheet sticking article, comprising a sticking step of sticking an adhesive sheet to an adherend, the adhesive sheet having an adhesive layer which is color-changeable and curable by irradiation of the 1 st active ray and curable by irradiation of the 2 nd active ray, the method comprising the steps of: a 1 st curing step of curing the adhesive layer on the adherend by irradiation of the 2 nd active ray to the adhesive layer; and a color-changing step of forming a color-changing portion in the adhesive layer by irradiating at least a part of the adhesive layer with the 1 st active light ray that is further downstream than the curing step, or the manufacturing method further includes the steps of: a 1 st color-changing curing step of irradiating the adhesive layer on the adherend with the 1 st active light to change the color of the adhesive layer and cure the adhesive layer, or the manufacturing method further includes the steps of: a 2 nd color-changing curing step of irradiating the 1 st active light beam to the 1 st part of the adhesive layer on the adherend to color and cure the 1 st part; and a 2 nd curing step of curing the 2 nd portion of the adhesive layer by irradiating the 2 nd portion with the 2 nd active light ray after the discoloration curing step.

The invention [2] comprises the method for producing an adhesive sheet attachment article according to [1], wherein the adhesive layer comprises: a polymerizable compound, a photopolymerization initiator, a compound that develops color by reaction with an acid, and a photoacid generator.

The invention [3] comprises the method for producing an adhesive sheet sticker according to [2], wherein the adhesive layer has a wavelength range in which the ratio of absorbance Y of the photopolymerization initiator to absorbance X of the photoacid generator is 2 or more in a range of 300nm to 500 nm.

The invention [4] comprises the method for producing an adhesive sheet adherend according to any of the above [1] to [3], wherein the 2 nd active ray in the curing step does not substantially contain light having a wavelength of less than 300 nm.

The invention [5] comprises the method for producing an adhesive sheet adherend according to any of the above [1] to [4], wherein in the curing step, at least one light source selected from the group consisting of a UV-LED lamp, a black light lamp, a high-pressure mercury lamp and a metal halide lamp is used as the light source of the 2 nd active light ray, and light from the light source is irradiated to the adhesive layer through a wavelength cut filter.

The invention [6] comprises the method for producing an adhesive sheet sticker according to any one of [1] to [5], wherein the 1 st active light ray in the discoloration step and/or the discoloration curing step contains light having a wavelength of less than 300 nm.

The invention [7] comprises the method for producing an adhesive sheet sticker according to any one of [1] to [6], wherein at least one light source selected from the group consisting of a UV-LED lamp, a black light lamp, a high-pressure mercury lamp and a metal halide lamp is used as the light source of the 1 st active light in the discoloration step and/or the discoloration curing step.

ADVANTAGEOUS EFFECTS OF INVENTION

In the method for producing an adhesive sheet attachment article of the present invention, in the attaching step, an adhesive sheet having an adhesive layer capable of changing color by irradiation of the 1 st active light is attached to an adherend. Therefore, at least a part of the pressure-sensitive adhesive layer can be discolored (discoloration step, 1 st discoloration curing step, or 2 nd discoloration curing step) by irradiation of the 1 st active light ray to the discoloration-scheduled part in the pressure-sensitive adhesive layer further after the bonding step. According to this manufacturing method, it is possible to check the presence or absence of foreign matter and air bubbles between the adhesive sheet and the adherend after the adhesion of the adhesive sheet to the adherend and before the formation of the discolored part of the adhesive layer.

In the present manufacturing method, the above-described configuration of the 1 st curing step and the subsequent discoloration step is suitable for forming a discoloration portion having a desired pattern shape in the adhesive layer by curing the adhesive layer while suppressing discoloration of the adhesive layer. The above-described constitution of carrying out the discoloration-curing step 1 is suitable for discoloration and curing of the adhesive layer with good overall efficiency. The above-described constitution of carrying out the 2 nd color-changing curing step and the 2 nd curing step thereafter is suitable for forming a color-changing portion of a desired pattern shape in the adhesive layer, and curing the adhesive layer while suppressing the color change other than the color-changing portion in the adhesive layer. Further, after the bonding step, it is preferable to form a color-changing portion in at least a part of the adhesive layer, and to secure flexibility suitable for bonding to an adherend when bonding these constituent adhesive layers (before curing) of the entire adhesive layer, and to suppress deterioration of the adhesive layer (after curing) and the color-changing portion of the adhesive sheet adhesive article to be manufactured.

Drawings

Fig. 1 shows a part of the steps of one embodiment of the method for producing an adhesive sheet product of the present invention. Fig. 1A shows a step of preparing an adhesive sheet and a 1 st member, fig. 1B shows a step of bonding the adhesive sheet to the 1 st member (bonding step), and fig. 1C shows a step of bonding the 1 st member and the 2 nd member via the adhesive sheet (bonding step).

Fig. 2 shows a process subsequent to that shown in fig. 1C. Fig. 2A shows a step of curing the adhesive layer of the adhesive sheet (the 1 st curing step), and fig. 2B shows a step of changing a color of a part of the adhesive layer of the adhesive sheet (the color changing step).

Fig. 3 shows another process following the process shown in fig. 1C. Specifically, a step of discoloring and curing the adhesive layer (1 st discoloration curing step) is shown.

Fig. 4 shows another process subsequent to the process shown in fig. 1C. Fig. 4A shows a step of discoloring and curing a part of the adhesive layer of the adhesive sheet (2 nd discoloration curing step), and fig. 4B shows a step of curing the adhesive layer of the adhesive sheet (2 nd curing step).

Fig. 5 is a schematic cross-sectional view of an adhesive sheet used in the method for producing an adhesive sheet attachment of the present invention.

Fig. 6 is a schematic cross-sectional view of a modification of the adhesive sheet used in the method for producing an adhesive sheet attachment article of the present invention (in the case where the adhesive sheet is a single-sided adhesive sheet with a base material).

Fig. 7 shows an adhesive sheet sticker manufactured using the adhesive sheet shown in fig. 6.

Detailed Description

Fig. 1A to 2B show an embodiment of a method for producing an adhesive sheet attachment article of the present invention. The manufacturing method comprises the following steps: a preparation process, a bonding process, a 1 st curing process and a color changing process.

First, in the preparation step, as shown in fig. 1A, the adhesive sheet S and the 1 st member M1 (adherend) are prepared.

The adhesive sheet S includes an adhesive layer 10. The pressure-sensitive adhesive sheet S has a sheet shape of a predetermined thickness, and extends in a direction (plane direction) orthogonal to the thickness direction. The adhesive layer 10 is a pressure-sensitive adhesive layer formed of an adhesive composition. The adhesive layer 10 has transparency (visible as-transmitted). The pressure-sensitive adhesive layer 10 is curable by irradiation of the 1 st active ray described later and is also curable by irradiation of the 2 nd active ray described later other than the 1 st active ray. The adhesive composition of the present embodiment contains a base polymer, a polymerizable compound, and a photopolymerization initiator. The photopolymerization initiator receives the 2 nd active light to initiate the polymerization reaction of the polymerizable compound. In the present embodiment, the adhesive composition uses a photoacid generator and a color former. The photoacid generator receives the 1 st active light ray to generate acid. The color-developing compound develops color by reaction with an acid. The components of the adhesive composition are more specifically, for example, as described below.

The 1 st member M1 is a display panel such as an organic EL panel. The 1 st member M1 may be other electronic devices and optical devices.

Next, in the bonding step, as shown in fig. 1B, the adhesive sheet S is bonded to the 1 st member M1. In the present embodiment, the pressure-sensitive adhesive sheet S is bonded to one surface of the 1 st member M1 in the thickness direction. Thus, the adhesive sheet S is disposed on one surface of the 1 st member M1 in the thickness direction.

After the bonding step, the presence or absence of foreign matter and air bubbles between the member M1 and the adhesive sheet S is checked as necessary.

In the present embodiment, next, as shown in fig. 1C, the 1 st member M1 and the 2 nd member M2 are joined via the adhesive sheet S (joining step). The 2 nd member M2 is, for example, a transparent substrate. Examples of the transparent substrate include a transparent plastic substrate and a transparent glass substrate. Through this step, a laminate W is obtained. In the laminate W, the adhesive sheet S is disposed so as to be in surface contact with one surface of the 1 st member M1 in the thickness direction, and the 2 nd member M2 is disposed so as to be in surface contact with one surface of the adhesive sheet S in the thickness direction.

After the bonding step, the presence or absence of foreign matter and air bubbles between the members M1, M2 and the adhesive sheet S is checked as necessary.

Next, in the 1 st curing step, as shown in fig. 2A, the adhesive layer 10 of the adhesive sheet S is cured. Specifically, the 2 nd active light is irradiated to the adhesive layer 10 in the laminate W, and the adhesive layer 10 is cured. The adhesive layer 10 is irradiated with the 2 nd active light from the transparent 2 member M2 side. Examples of the light source for irradiation of the 2 nd active light include an ultraviolet LED lamp (UV-LED lamp), a black light lamp, a high-pressure mercury lamp, and a metal halide lamp. In addition, in the irradiation of the 2 nd active light ray, a wavelength cut filter for cutting off a wavelength region of a part of the light rays emitted from the light source may be used as necessary. The same applies to the type of the light source for the 2 nd active ray and the use of the wavelength cut filter at the time of irradiation of the 2 nd active ray, and the 2 nd curing step described later.

The wavelength range of the 2 nd active ray is different from that of the 1 st active ray. The 2 nd active ray in this embodiment has a wavelength at which substantially no acid is generated in the photoacid generator. The 2 nd active ray preferably contains substantially no light of a wavelength below 300 nm. The lower limit of the wavelength range of the 2 nd active light is preferably 300nm, more preferably 320nm, still more preferably 340nm, still more preferably 360nm, still more preferably 380nm, still more preferably 390nm, particularly preferably 395nm. In this embodiment, it is preferable to use a photopolymerization initiator for initiating the polymerization reaction of the polymerizable compound by irradiation with light of such a wavelength in the adhesive composition. The same applies to the above configuration concerning the wavelength of the 2 nd active light, and the 2 nd active light used in the 2 nd curing step described later.

In this step, the polymerization reaction of the polymerizable compound is initiated by the photopolymerization initiator in the adhesive layer 10 irradiated with the 2 nd active light, and the polymerization reaction proceeds. Thereby, the elastic modulus of the adhesive layer 10 increases.

The pressure-sensitive adhesive layer 10 preferably has a wavelength region (wavelength region R) in which the ratio of the absorbance Y of the photopolymerization initiator to the absorbance X of the photoacid generator used is 2 or more in the range of 300nm to 500 nm. The aforementioned ratio (Y/X) in the wavelength region R is preferably 3 or more, more preferably 10 or more, and further preferably 100 or more. Preferably, at least a portion of the wavelength of the 2 nd active light is located within the wavelength region R. More preferably, all of the wavelengths of the 2 nd active light are located within the wavelength region R. In the curing step of irradiating the adhesive layer 10 with the 2 nd active light having a wavelength in such a wavelength region, the adhesive layer 10 is cured while suppressing discoloration in the adhesive layer 10. In the curing step, from the viewpoint of curing the adhesive layer 10 while suppressing discoloration in the adhesive layer 10, the above ratio of the absorbance Y of the photopolymerization initiator to the absorbance X of the photoacid generator is preferably larger.

For the adhesive layer 10 after curing, the shear storage modulus at 25℃expressed in the dynamic viscoelasticity measurement at a frequency of 1Hz and a heating rate of 5 ℃/min (1 st shear storage modulus) is preferably 0.2X10 ⁵ Pa or more, more preferably 2X 10 ⁵ Pa or more, more preferably 5X 10 ⁵ Pa or more. The shear storage modulus is preferably 100X 10 ⁵ Pa or less, more preferably 50X 10 ⁵ Pa or less, more preferably 25×10 ⁵ Pa or below. In addition, the shear storage modulus (2 nd shear storage modulus) at 25℃expressed in the dynamic viscoelasticity measurement under the conditions of a frequency of 1Hz and a heating rate of 5 ℃/min is preferably 0.1X10 for the adhesive layer 10 before curing ⁵ Pa or more, more preferably 0.2X10 ⁵ Pa or more, more preferably 0.3X10 ⁵ Pa or more. The 1 st shear storage modulus is preferably 10X 10 ⁵ Pa or less, more preferably 5×10 ⁵ Pa or below, inOne step preferably 3X 10 ⁵ Pa or below. The ratio of the 1 st shear storage modulus to the 2 nd shear storage modulus is preferably 2 or more, more preferably 5 or more, and still more preferably 10 or more. The same ratio is preferably 100 or less, more preferably 50 or less, and still more preferably 30 or less. The above constitution involving the shear storage modulus is suitable for suppressing deterioration of the discoloration portion formed in the adhesive layer 10, which will be described later.

Next, in the color change step, as shown in fig. 2B, at least a part of the pressure-sensitive adhesive layer 10 of the pressure-sensitive adhesive sheet S is changed in color. Specifically, the color change portion 11 is formed in the adhesive layer 10 by irradiation of at least a part of the adhesive layer 10 in the laminate W with the 1 st active light ray (in fig. 2B, a case where the color change portion 11 is formed in a part of the adhesive layer 10 is exemplarily illustrated). In this step, when the color change portion 11 is formed in a part of the pressure-sensitive adhesive layer 10, the 1 st active light is irradiated onto the pressure-sensitive adhesive layer 10 from the transparent 2 nd member M2 side through a mask pattern (not shown) for masking a predetermined region in the pressure-sensitive adhesive layer 10. Thereby, the portion of the adhesive layer 10 that is not masked by the mask pattern is discolored.

Examples of the 1 st active light irradiation light source include an ultraviolet LED lamp (UV-LED lamp), a black light lamp, a high-pressure mercury lamp, and a metal halide lamp. In addition, in the irradiation of the 1 st active light ray, a wavelength cut filter for cutting off a wavelength region of a part of the 1 st active light ray emitted from the light source may be used as necessary. The same applies to the type of the light source for the 1 st active ray and the use of the wavelength cut filter at the time of irradiation of the 1 st active ray, and the 1 st color change curing step and the 2 nd color change curing step described later.

The wavelength range of the 1 st active ray is different from that of the 2 nd active ray. The wavelength range of the 1 st active ray preferably includes a range smaller than at least the wavelength range of the 2 nd active ray (wavelength range on the short wavelength side) (the wavelength range of the 1 st active ray may also include a range overlapping with the wavelength range of the 2 nd active ray). That is, the 1 st active ray preferably includes a high-energy ray not included in the 2 nd active ray. For example, the 1 st active ray contains light of a wavelength below 300 nm.

When the 1 st active light ray has a lower limit in the wavelength range, or when the lower limit is set in the wavelength range of the 1 st active light ray using, for example, a wavelength cut-off filter, the lower limit of the wavelength range of the 1 st active light ray is preferably 200nm, more preferably 220nm, further preferably 240nm, further preferably 250nm, further preferably 260nm, further preferably 270nm, particularly preferably 280nm. Alternatively, the 1 st active light ray may include light having a wavelength of less than 200 nm. Examples of the light source of such light include a high-pressure mercury lamp and a metal halide lamp. When the 1 st active light ray has an upper limit in the wavelength range, or when the upper limit is set in the wavelength range of the 1 st active light ray using, for example, a wavelength cut-off filter, the upper limit of the wavelength range of the 1 st active light ray is preferably 400nm, more preferably 395nm, still more preferably 390nm, still more preferably 385nm, still more preferably 380nm, still more preferably 375nm, and particularly preferably 370nm. In this embodiment, it is preferable to use a photoacid generator that generates an acid by irradiation with an active energy ray having such a wavelength in the adhesive composition. The same applies to the 1 st active ray used in the 1 st color change curing step and the 2 nd color change curing step described below, regarding the above configuration concerning the wavelength of the 1 st active ray.

In this step, the 1 st active light is irradiated to the pressure-sensitive adhesive layer 10, and an acid is generated from the photoacid generator, and the color-developing compound develops color by reacting with the acid. Thereby, the color change portion 11 is formed in the adhesive layer 10. The color change portion 11 is, for example, dark.

As described above, the adhesive sheet attachment Z can be manufactured. In the case where the 1 st member M1 is a display panel such as an organic EL panel, external light reflection in the metal wiring can be suppressed by providing the color change portion 11 in a pattern shape corresponding to (i.e., facing) the metal wiring formed on the pixel panel provided in the panel.

In the present manufacturing method, after the process shown in fig. 1C, the following 1 st color-changing curing process may be performed instead of the process shown in fig. 2A and 2B.

In the 1 st color-change curing step, as shown in fig. 3, the pressure-sensitive adhesive layer 10 of the pressure-sensitive adhesive sheet S is color-changed and cured. Specifically, the adhesive layer 10 in the laminate W is irradiated with the 1 st active light, so that the entire adhesive layer 10 is cured and discolored. The 1 st active light is irradiated to the adhesive layer 10 from the transparent 2 nd member M2 side.

In this step, the adhesive layer 10 irradiated with the 1 st active light generates an acid from the photoacid generator, and the color-developing compound develops color by reacting with the acid. Thereby, the adhesive layer 10 changes color (the color change portion 11 is formed in the whole of the adhesive layer 10). In this step, the polymerization reaction of the polymerizable compound is initiated by the photopolymerization initiator in the adhesive layer 10 irradiated with the 1 st active light, and the polymerization reaction proceeds. Thereby, the elastic modulus of the adhesive layer 10 increases.

The adhesive sheet sticker Z can also be manufactured by the above method.

In the present manufacturing method, after the process shown in fig. 1C, the following 2 nd color change curing process and 2 nd curing process may be performed instead of the processes shown in fig. 2A and 2B.

In the 2 nd color-change curing step, as shown in fig. 4A, a part of the adhesive layer 10 of the adhesive sheet S is color-changed and cured. Specifically, the 1 st active light beam irradiates a part (1 st part) of the adhesive layer 10 in the laminate W, thereby forming the color change portion 11 in the part of the adhesive layer 10, and curing the part. In this step, the 1 st active light is irradiated onto the pressure-sensitive adhesive layer 10 from the transparent 2 nd member M2 side through a mask pattern (not shown) for masking a predetermined region in the pressure-sensitive adhesive layer 10.

In this step, an acid is generated from the photoacid generator in the portion of the pressure-sensitive adhesive layer 10 irradiated with the 1 st active light, and the color-developing compound develops color by reacting with the acid. Thereby, the color change portion 11 is formed in the adhesive layer 10. In this step, the polymerization reaction of the polymerizable compound is initiated by the photopolymerization initiator in the portion of the adhesive layer 10 irradiated with the 1 st active light, and the polymerization reaction proceeds. Thereby, the elastic modulus of the portion increases.

In the 2 nd curing step, as shown in fig. 4B, the adhesive layer 10 of the adhesive sheet S is cured. Specifically, at least a part of the adhesive layer 10 in the laminate W is irradiated with the 2 nd active light, and the adhesive layer 10 is cured. The region of the adhesive layer 10 to which the 2 nd active light is irradiated includes any portion (2 nd portion) other than the color-changing portion 11 of the adhesive layer 10, and is preferably the entire adhesive layer 10. The 2 nd active light is irradiated to the adhesive layer 10 from the transparent 2 nd member M2 side.

In this step, the polymerization reaction of the polymerizable compound is initiated by the photopolymerization initiator in the adhesive layer 10 irradiated with the 2 nd active light, and the polymerization reaction proceeds. As a result, the elastic modulus of the adhesive layer 10 increases (fig. 4B schematically illustrates a case where the entire adhesive layer 10 is cured).

In the above manufacturing method, the adhesive sheet S including the adhesive layer 10 which is capable of changing color afterwards by irradiation of the 1 st active light is bonded to the 1 st member M1 as the adherend (bonding step). Further, the 1 st member M1 and the 2 nd member M2 as an adherend are joined together by the pressure-sensitive adhesive sheet S (joining step). According to this manufacturing method, after the bonding step and before the color change portion 11 of the pressure-sensitive adhesive layer 10 is formed, the presence or absence of foreign matter and bubbles between the pressure-sensitive adhesive sheet S and the adherend can be checked.

In the present manufacturing method, the above-described configuration (shown in fig. 2A and 2B) in which the 1 st curing step and the subsequent discoloration step are performed is suitable for forming the discoloration portion 11 having a desired pattern shape in the adhesive layer 10 while curing the adhesive layer 10 while suppressing the discoloration of the adhesive layer 10. The above-described configuration (shown in fig. 3) for performing the 1 st color-changing curing step is suitable for efficiently changing and curing the entire adhesive layer 10. The above-described constitution (shown in fig. 4A and 4B) in which the 2 nd color change curing step and the subsequent 2 nd curing step are performed is suitable for forming the color change portion 11 of a desired pattern shape in the adhesive layer 10 and curing the adhesive layer 10 while suppressing the color change other than the color change portion 11 in the adhesive layer 10. Further, these configurations, which are suitable for forming the color change portion 11 in the adhesive layer 10 after the bonding step and curing the entire adhesive layer 10, are suitable for suppressing deterioration of the color change portion 11 in the adhesive layer 10 (after curing) while ensuring flexibility suitable for bonding to an adherend in the adhesive layer 10 (before curing). The deterioration of the color change portion 11 includes, for example, deformation of the color change portion 11 caused by deformation of the adhesive layer 10. The deterioration of the color-changing portion 11 may include, for example, bleeding, discoloration, and unevenness in color appearance of the color-changing portion 11 due to diffusion of the color-developing compound contained in the color-changing portion 11.

The adhesive composition of the adhesive layer 10 forming the adhesive sheet S includes, for example: a base polymer, a polymerizable compound, a photopolymerization initiator, a photoacid generator, and a color-developing compound.

The base polymer is an adhesive component for exhibiting adhesiveness in the adhesive layer 10. The base polymer exhibits rubber elasticity in the room temperature range. Examples of the base polymer include acrylic polymers, rubber polymers, polyester polymers, urethane polymers, polyether polymers, silicone polymers, polyamide polymers, and fluoropolymers. From the viewpoint of ensuring good transparency and adhesion in the adhesive layer 10, an acrylic polymer is preferably used as the base polymer.

The content ratio of the base polymer in the pressure-sensitive adhesive layer 10 is preferably 50% by mass or more, more preferably 60% by mass or more, and still more preferably 70% by mass or more, from the viewpoint of appropriately exhibiting the function of the base polymer in the pressure-sensitive adhesive layer 10.

The acrylic polymer is, for example, a polymer obtained by polymerizing a monomer component containing a (meth) acrylic acid ester at a ratio of 50 mass% or more. "(meth) acrylic" refers to acrylic and/or methacrylic.

Examples of the (meth) acrylic acid ester include alkyl (meth) acrylate and alkoxyalkyl (meth) acrylate.

Examples of the alkyl (meth) acrylate include alkyl (meth) acrylates having a linear or branched alkyl group having 1 to 20 carbon atoms. Examples of such alkyl (meth) acrylates include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n-butyl (meth) acrylate, isopropyl (meth) acrylate, isobutyl (meth) acrylate, sec-butyl (meth) acrylate, tert-butyl (meth) acrylate, pentyl (meth) acrylate, isopentyl (meth) acrylate, neopentyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, octyl (meth) acrylate, isooctyl (meth) acrylate, nonyl (meth) acrylate, isononyl (meth) acrylate, decyl (meth) acrylate, isodecyl (meth) acrylate, undecyl (meth) acrylate, dodecyl (meth) acrylate, isotridecyl (meth) acrylate, tetradecyl (meth) acrylate, isotetradecyl (meth) acrylate, pentadecyl (meth) acrylate, hexadecyl (meth) acrylate, heptadecyl (meth) acrylate, octadecyl (meth) acrylate, nonadecyl (meth) acrylate and eicosanyl (meth) acrylate. (As the alkyl (meth) acrylate, an alkyl acrylate having an alkyl group of 1 to 12 carbon atoms is preferably used, more preferably a combination of methyl acrylate and an alkyl acrylate having an alkyl group of 2 to 12 carbon atoms, still more preferably a combination of methyl acrylate and 2-ethylhexyl acrylate.

Examples of the alkoxyalkyl (meth) acrylate include alkoxyalkyl (meth) acrylates having an alkoxy group having 1 to 4 carbon atoms and an alkylene group having 1 to 4 carbon atoms. Examples of such alkoxyalkyl (meth) acrylates include 2-methoxymethyl (meth) acrylate, 2-methoxyethyl (meth) acrylate, 2-ethoxymethyl (meth) acrylate, 2-ethoxyethyl (meth) acrylate, 3-methoxypropyl (meth) acrylate, 3-ethoxypropyl (meth) acrylate, 4-methoxybutyl (meth) acrylate, and 4-ethoxybutyl (meth) acrylate. As the alkoxyalkyl (meth) acrylate, 2-ethoxymethyl (meth) acrylate is preferably used, and 2-ethoxymethyl acrylate is more preferably used.

The (meth) acrylic acid esters may be used alone or in combination of two or more.

The proportion of the (meth) acrylic acid ester in the monomer component is preferably 50% by mass or more, more preferably 60% by mass or more, and still more preferably 70% by mass or more, from the viewpoint of appropriately exhibiting basic characteristics such as adhesiveness in the adhesive layer 10. The same ratio is, for example, 99 mass% or less.

The monomer component may comprise a copolymerizable monomer copolymerizable with the (meth) acrylate. Examples of the copolymerizable monomer include monomers having a polar group. Examples of the polar group-containing monomer include a hydroxyl group-containing monomer, a monomer having a nitrogen atom-containing ring, and a carboxyl group-containing monomer. The polar group-containing monomer is advantageous for modification of the acrylic polymer such as introduction of the crosslinking point into the acrylic polymer and securing of the aggregation force of the acrylic polymer.

The copolymerizable monomer preferably contains at least one selected from the group consisting of a hydroxyl group-containing monomer, a monomer having a nitrogen atom-containing ring, and a carboxyl group-containing monomer. More preferably, the copolymerizable monomer contains a hydroxyl group-containing monomer and/or a monomer having a nitrogen atom-containing ring.

Examples of the hydroxyl group-containing monomer include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, 8-hydroxyoctyl (meth) acrylate, 10-hydroxydecyl (meth) acrylate, 12-hydroxylauryl (meth) acrylate and (4-hydroxymethylcyclohexyl) methyl (meth) acrylate. As the hydroxyl group-containing monomer, 2-hydroxyethyl (meth) acrylate is preferably used, and 2-hydroxyethyl acrylate is more preferably used.

The proportion of the hydroxyl group-containing monomer in the monomer component is preferably 1% by mass or more, more preferably 3% by mass or more, and still more preferably 5% by mass or more, from the viewpoints of introducing the crosslinked structure into the acrylic polymer and securing the aggregation force in the adhesive layer 10. The same ratio is preferably 30 mass% or less, more preferably 20 mass% or less, from the viewpoints of adjustment of the viscosity of a polymerization reaction solution at the time of polymerization of an acrylic polymer and adjustment of the polarity of the acrylic polymer (concerning compatibility of various additive components in the adhesive layer 10 with the acrylic polymer).

Examples of the monomer having a nitrogen atom-containing ring include N-vinyl-2-pyrrolidone, N-methyl vinylpyrrolidone, N-vinylpyridine, N-vinylpiperidone, N-vinylpyridine, N-vinylpiperazine, N-vinylpyrzine, N-vinylpyrrolidone, N-vinylimidazole, N-vinyloxazole, N- (meth) acryl-2-pyrrolidone, N- (meth) acryl piperidine, N- (meth) acryl pyrrolidine, N-vinylmorpholine, N-vinyl-3-morpholone, N-vinyl-2-caprolactam, N-vinyl-1, 3-oxazin-2-one, N-vinyl-3, 5-morpholinedione, N-vinylpyrazole, N-vinylisoxazole, N-vinylthiazole and N-vinylisothiazole. As the monomer having a nitrogen atom-containing ring, N-vinyl-2-pyrrolidone is preferably used.

The proportion of the monomer having a nitrogen atom-containing ring in the monomer component is preferably 1% by mass or more, more preferably 3% by mass or more, and still more preferably 5% by mass or more, from the viewpoints of securing the aggregation force in the pressure-sensitive adhesive layer 10 and securing the adhesion force to the adherend in the pressure-sensitive adhesive layer 10. The same ratio is preferably 30 mass% or less, more preferably 20 mass% or less, from the viewpoints of adjustment of the glass transition temperature of the acrylic polymer and adjustment of the polarity of the acrylic polymer (concerning compatibility of various additive components in the adhesive layer 10 with the acrylic polymer).

Examples of the carboxyl group-containing monomer include acrylic acid, methacrylic acid, carboxyethyl acrylate, carboxypentyl acrylate, itaconic acid, maleic acid, fumaric acid, crotonic acid, and isocrotonic acid.

The ratio of the carboxyl group-containing monomer in the monomer component is preferably 1% by mass or more, more preferably 3% by mass or more, and still more preferably 5% by mass or more, from the viewpoints of introduction of the crosslinked structure into the acrylic polymer, securing of the aggregation force in the adhesive layer 10, and securing of the adhesion force to the adherend in the adhesive layer 10. The same ratio is preferably 30 mass% or less, more preferably 20 mass% or less, from the viewpoints of adjustment of the glass transition temperature of the acrylic polymer and avoidance of corrosion risk of the adherend due to acid.

The monomer component may comprise other copolymerizable monomers. Examples of the other copolymerizable monomer include acid anhydride monomers, sulfonic acid group-containing monomers, phosphoric acid group-containing monomers, epoxy group-containing monomers, cyano group-containing monomers, amide group-containing monomers, monomers having a succinimide skeleton, maleimides, itaconimides, alkoxy group-containing monomers, vinyl esters, vinyl ethers, and aromatic vinyl compounds.

Examples of the acid anhydride monomer include maleic anhydride and itaconic anhydride.

Examples of the sulfonic acid group-containing monomer include styrene sulfonic acid, allyl sulfonic acid, sodium vinylsulfonate, 2- (meth) acrylamide-2-methylpropanesulfonic acid, (meth) acrylamide propane sulfonic acid, sulfopropyl (meth) acrylate, and (meth) acryloxynaphthalene sulfonic acid.

Examples of the phosphate group-containing monomer include 2-hydroxyethyl acryloyl phosphate.

Examples of the epoxy group-containing monomer include epoxy group-containing acrylates such as glycidyl (meth) acrylate and 2-ethyl glycidyl (meth) acrylate, allyl glycidyl ether, and glycidyl (meth) acrylate.

Examples of the cyano group-containing monomer include acrylonitrile and methacrylonitrile.

Examples of the amide group-containing monomer include N-vinylcarboxylic acid amides such as (meth) acrylamide, N-dialkyl (meth) acrylamide, N-alkyl (meth) acrylamide and N-vinylacetamide, N-hydroxyalkyl (meth) acrylamides, N-alkoxyalkyl (meth) acrylamides, N-dimethylaminopropyl (meth) acrylamide and N- (meth) acryloylmorpholine. Examples of the N, N-dialkyl (meth) acrylamides include N, N-dimethyl (meth) acrylamide, N-diethyl (meth) acrylamide, N-dipropyl (meth) acrylamide, N-diisopropyl (meth) acrylamide, N-di (N-butyl) (meth) acrylamide and N, N-di (t-butyl) (meth) acrylamide. Examples of the N-alkyl (meth) acrylamide include N-ethyl (meth) acrylamide, N-isopropyl (meth) acrylamide, N-butyl (meth) acrylamide, and N-N-butyl (meth) acrylamide. Examples of the N-hydroxyalkyl (meth) acrylamide include N- (2-hydroxyethyl) (meth) acrylamide, N- (2-hydroxypropyl) (meth) acrylamide, N- (1-hydroxypropyl) (meth) acrylamide, N- (3-hydroxypropyl) (meth) acrylamide, N- (2-hydroxybutyl) (meth) acrylamide, N- (3-hydroxybutyl) (meth) acrylamide, and N- (4-hydroxybutyl) (meth) acrylamide. Examples of the N-alkoxyalkyl (meth) acrylamide include N-methoxymethyl (meth) acrylamide, N-methoxyethyl (meth) acrylamide, and N-butoxymethyl (meth) acrylamide.

Examples of the monomer having a succinimide skeleton include N- (meth) acryloyloxymethylene succinimide, N- (meth) acryl-6-oxyhexamethylene succinimide, and N- (meth) acryl-8-oxyhexamethylene succinimide.

Examples of the maleimides include N-cyclohexylmaleimide, N-isopropylmaleimide, N-laurylmaleimide and N-phenylmaleimide.

Examples of the itaconimides include N-methyl itaconimide, N-ethyl itaconimide, N-butyl itaconimide, N-octyl itaconimide, N-2-ethylhexyl itaconimide, N-cyclohexyl itaconimide and N-month Gui Jiyi itaconimide.

Examples of the alkoxy group-containing monomer include alkoxyalkyl (meth) acrylates and alkoxyalkyleneglycol (meth) acrylates. Examples of the alkoxyalkyl (meth) acrylate include 2-methoxyethyl (meth) acrylate, 3-methoxypropyl (meth) acrylate, 2-ethoxyethyl (meth) acrylate, propoxyethyl (meth) acrylate, butoxyethyl (meth) acrylate, and ethoxypropyl (meth) acrylate. Examples of the alkoxyalkylene glycol (meth) acrylate include methoxyethylene glycol (meth) acrylate and methoxypolypropylene glycol (meth) acrylate.

Examples of vinyl esters include vinyl acetate and vinyl propionate.

Examples of vinyl ethers include methyl vinyl ether and ethyl vinyl ether.

Examples of the aromatic vinyl compound include styrene, α -methylstyrene and vinyltoluene. Examples of the olefins include ethylene, butadiene, isoprene and isobutylene.

The copolymerizable monomer may be used alone or in combination of two or more.

The acrylic polymer can be formed by polymerizing the above monomer components. Examples of the polymerization method include solution polymerization, bulk polymerization and emulsion polymerization, and preferably include solution polymerization. In solution polymerization, for example, a reaction solution is prepared by compounding a monomer component and a polymerization initiator in a solvent, and then the reaction solution is heated. Then, the polymerization reaction of the monomer components in the reaction solution is performed, whereby an acrylic polymer solution containing an acrylic polymer can be obtained. As the polymerization initiator, for example, a thermal polymerization initiator is used. The amount of the polymerization initiator is, for example, 0.05 parts by mass or more and 1 part by mass or less based on 100 parts by mass of the monomer component.

Examples of the thermal polymerization initiator include azo polymerization initiators and peroxide polymerization initiators. Examples of the azo polymerization initiator include 2,2' -azobisisobutyronitrile, 2' -azobis-2-methylbutyronitrile, dimethyl 2,2' -azobis (2-methylpropionate), 4' -azobis-4-cyanovaleric acid, azobisisovaleronitrile, 2' -azobis (2-amidinopropane) dihydrochloride, 2' -azobis [2- (5-methyl-2-imidazolin-2-yl) propane ] dihydrochloride, 2' -azobis (2-methylpropionamidine) disulfate and 2,2' -azobis (N, N ' -dimethyleneisobutyl amidine) dihydrochloride. Examples of the peroxide polymerization initiator include dibenzoyl peroxide, t-butyl peroxymaleate, and lauroyl peroxide.

The weight average molecular weight of the acrylic polymer is preferably 100000 or more, more preferably 300000 or more, and even more preferably 500000 or more from the viewpoint of securing the aggregation force in the adhesive layer 10. The same weight average molecular weight is preferably 5000000 or less, more preferably 3000000 or less, and further preferably 2000000 or less. The weight average molecular weight of the acrylic polymer was measured by Gel Permeation Chromatography (GPC), and calculated from polystyrene conversion.

The glass transition temperature (Tg) of the base polymer is preferably 0℃or lower, more preferably-10℃or lower, and still more preferably-20℃or lower. The same glass transition temperature is, for example, -80 ℃ or higher.

For the glass transition temperature (Tg) of the polymer, a glass transition temperature (theoretical value) obtained based on the following Fox formula can be used. The Fox formula is a relation between the glass transition temperature Tg of the polymer and the glass transition temperature Tgi of the homopolymer of the monomers constituting the polymer. In the following Fox formula, tg represents the glass transition temperature (. Degree. C.) of the polymer, wi represents the weight fraction of the monomer i constituting the polymer, tgi represents the glass transition temperature (. Degree. C.) of the homopolymer formed from the monomer i. As the glass transition temperature of the homopolymer, literature values such as "Polymer Handbook" (4 th edition, john Wiley & Sons, inc., 1999) and "synthetic resin for New Polymer library 7 paint" are used (Santa Clara, north Korea, polymer journal, 1995) to list the glass transition temperatures of various homopolymers. On the other hand, the glass transition temperature of the homopolymer of the monomer can be obtained by a method specifically described in JP-A2007-51271.

Fox 1/(273+tg) =Σ [ Wi/(273+tgi) ]

The adhesive composition may contain a crosslinking agent from the viewpoint of introducing a crosslinked structure into the base polymer. Examples of the crosslinking agent include isocyanate crosslinking agents, epoxy crosslinking agents, oxazoline crosslinking agents, aziridine crosslinking agents, carbodiimide crosslinking agents, and metal chelate crosslinking agents. The crosslinking agent may be used alone, or two or more thereof may be used in combination.

Examples of the isocyanate crosslinking agent include toluene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, xylene diisocyanate, hydrogenated xylene diisocyanate, diphenylmethane diisocyanate, hydrogenated diphenylmethane diisocyanate, tetramethylxylene diisocyanate, naphthalene diisocyanate, triphenylmethane triisocyanate, and polymethylene polyphenyl isocyanate. Further, as the isocyanate crosslinking agent, derivatives of these isocyanates can be mentioned. Examples of the isocyanate derivative include isocyanurate modified products and polyol modified products. Examples of the commercial products of the isocyanate crosslinking agent include CORONATE L (trimethylolpropane adduct of toluene diisocyanate, manufactured by eastern corporation), CORONATE HL (trimethylolpropane adduct of hexamethylene diisocyanate, manufactured by eastern corporation), CORONATE HX (isocyanurate body of hexamethylene diisocyanate, manufactured by eastern corporation), and TAKENATE D N (trimethylolpropane adduct of xylene diisocyanate, manufactured by three-well chemistry).

Examples of the epoxy crosslinking agent include bisphenol a, epichlorohydrin type epoxy resins, ethylene glycidyl ether, polyethylene glycol diglycidyl ether, glycerol triglycidyl ether, 1, 6-hexanediol glycidyl ether, trimethylolpropane triglycidyl ether, diglycidyl aniline, diamine glycidyl amine, N' -tetraglycidyl-m-xylylenediamine, and 1, 3-bis (N, N-diglycidyl aminomethyl) cyclohexane.

The amount of the crosslinking agent to be blended is, for example, 0.01 parts by mass or more, preferably 0.05 parts by mass or more, and more preferably 0.07 parts by mass or more, relative to 100 parts by mass of the base polymer, from the viewpoint of securing the aggregation power of the adhesive layer 10. From the viewpoint of ensuring good tackiness in the pressure-sensitive adhesive layer 10, the amount of the crosslinking agent blended per 100 parts by mass of the base polymer is, for example, 10 parts by mass or less, preferably 5 parts by mass or less, and more preferably 3 parts by mass or less.

When a crosslinking structure is introduced into the base polymer, a crosslinking catalyst may be used in order to allow the crosslinking reaction to proceed efficiently. Examples of the crosslinking catalyst include dibutyltin dilaurate, tetra-n-butyl titanate, tetra-isopropyl titanate, iron acetylacetonate, and butyltin oxide, and dibutyltin dilaurate is preferably used. The amount of the crosslinking catalyst used is, for example, 0.0001 parts by mass or more and 1 part by mass or less based on 100 parts by mass of the base polymer.

In the case of using the crosslinking catalyst, a crosslinking inhibitor which can be removed later from the adhesive composition may be blended in the adhesive composition. In the case of using dibutyltin dilaurate as the crosslinking catalyst, acetylacetone is preferably used as the crosslinking inhibitor. In this case, in the adhesive composition, acetylacetone coordinates to dibutyltin dilaurate, and the crosslinking reaction of the crosslinking agent with respect to the base polymer is suppressed. In the process of producing the adhesive sheet S described later, the adhesive composition is applied to a release film to form a coating film, and then the coating film is heated at a desired time to volatilize the acetylacetone, thereby removing the acetylacetone from the coating film. Thereby, the crosslinking reaction of the crosslinking agent can be performed.

The blending amount of the crosslinking inhibitor is, for example, 100 parts by mass or more, preferably 1000 parts by mass or more, relative to 100 parts by mass of the crosslinking catalyst. The same amount is, for example, 5000 parts by mass or less.

The polymerizable compound is a compound having a polymerizable functional group. The polymerizable functional group has an ethylenically unsaturated double bond. Examples of the polymerizable functional group include a (meth) acryloyl group, an ethenyl group, and an propenyl group. Examples of the polymerizable compound include a monomer having one polymerizable functional group (monofunctional monomer) and a monomer having a plurality of polymerizable functional groups (polyfunctional monomer). In addition, as the polymerizable compound, a compound having a (meth) acryloyl group is used as the polymerizable functional group from the viewpoint of reactivity. (meth) acryl means acryl and/or methacryl. The polymerizable compounds may be used alone or in combination of two or more.

As the monofunctional monomer, there is used, examples thereof include ethyl (meth) acrylate, n-butyl (meth) acrylate, t-butyl (meth) acrylate, isobutyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isodecyl (meth) acrylate, butoxydiglycol (meth) acrylate, methoxypolyethylene glycol (meth) acrylate, glycidyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, caprolactone-modified tetrahydrofurfuryl (meth) acrylate, cyclohexyl (meth) acrylate, dicyclopentanyl (meth) acrylate, dicyclopentenyl oxy (meth) acrylate, isobornyl (meth) acrylate, adamantyl (meth) acrylate, benzyl (meth) acrylate, phenoxyethyl (meth) acrylate, phenoxydiethylene glycol (meth) acrylate, phenoxytetraethylene glycol (meth) acrylate, nonylphenoxyethyl (meth) acrylate, butoxyethyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxy (meth) acrylate, glycerin (meth) acrylate, and the like Trifluoroethyl (meth) acrylate, methacryloxyethyl acid phosphate, 2-hydroxyethyl methacrylate phosphate, gamma-methacryloxypropyl trimethoxysilane, gamma-acryloxypropyl trimethoxysilane, acryloylmorpholine, morpholinoethyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, and N, N-dimethylaminoethyl (meth) acrylate.

Examples of the polyfunctional monomer include difunctional monomers, trifunctional monomers, and polyfunctional monomers having four or more functions.

Examples of the difunctional monomer include ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, tetraethylene glycol dimethacrylate, 1, 6-hexanediol di (meth) acrylate, 1, 9-nonanediol di (meth) acrylate, glycerol di (meth) acrylate, neopentyl glycol di (meth) acrylate, stearic acid modified pentaerythritol di (meth) acrylate, dicyclopentadienyl diacrylate, di (meth) acryl isocyanurate, and alkylene oxide modified bisphenol di (meth) acrylate.

Examples of the trifunctional monomer include trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, and tris (acryloxyethyl) isocyanurate.

Examples of the polyfunctional monomer having four or more functions include di (trimethylol) propane tetra (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol monohydroxy penta (meth) acrylate, alkyl-modified dipentaerythritol pentaacrylate, dipentaerythritol hexa (meth) acrylate, and isocyanuric acid EO-modified di-and triacrylate.

From the viewpoint of rapid curability of the pressure-sensitive adhesive layer 10, a polyfunctional monomer is preferably used as the polymerizable compound, more preferably a polyfunctional monomer having four or more functions is more preferably used, and further preferably dipentaerythritol hexa (meth) acrylate is used, and particularly preferably dipentaerythritol hexa acrylate is used.

The amount of the polymerizable compound to be blended is preferably 5 parts by mass or more, more preferably 7 parts by mass or more, still more preferably 9 parts by mass or more, and particularly preferably 10 parts by mass or more, based on 100 parts by mass of the base polymer, from the viewpoint of securing sufficient hardness in the cured adhesive layer 10. From the viewpoint of ensuring sufficient adhesive force in the cured adhesive layer 10, the amount of the polymerizable compound to be blended is preferably 50 parts by mass or less, more preferably 45 parts by mass or less, and still more preferably 43 parts by mass or less, relative to 100 parts by mass of the base polymer.

The photopolymerization initiator initiates the polymerization reaction of the polymerizable compound. Examples of the photopolymerization initiator include benzoin ether photopolymerization initiator, acetophenone photopolymerization initiator, α -ketol photopolymerization initiator, aromatic sulfonyl chloride photopolymerization initiator, photoactive oxime photopolymerization initiator, benzoin photopolymerization initiator, benzyl photopolymerization initiator, benzophenone photopolymerization initiator, ketal photopolymerization initiator, thioxanthone photopolymerization initiator, and acylphosphine oxide photopolymerization initiator.

Examples of the photoacid generator (1 st photoacid generator) include onium compounds that generate acid by ultraviolet irradiation (1 st active light). The onium compound is provided, for example, in the form of an onium salt of an onium cation and an anion. Examples of onium cations include iodonium and sulfonium. Examples of the anions include Cl ^- ，Br ^- ，I ^- ，ZnCl ₃ ^- ，HSO ₃ ^- ，BF ₄ ^- ，PF ₆ ^- ，AsF ₆ ^- ，SbF ₆ ^- ，CH ₃ SO ₃ ^- ，CF ₃ SO ₃ ^- ，C ₄ F ₉ HSO ₃ ^- ，(C ₆ F ₅ ) ₄ B ^- And (C) ₄ H ₉ ) ₄ B ^- . The photoacid generator may be used alone or in combination of two or more. The adhesive composition preferably comprises sulfonium and C ₄ F ₉ HSO ₃ ^- The onium salt (onium compound) formed acts as photoacid generator.

The blending amount of the photoacid generator is preferably 1 part by mass or more, more preferably 2 parts by mass or more, further preferably 5 parts by mass or more, particularly preferably 7 parts by mass or more, relative to 100 parts by mass of the base polymer. The same blending amount is preferably 20 parts by mass or less, more preferably 15 parts by mass or less, and still more preferably 12 parts by mass or less.

The amount of the photoacid generator to be blended per 100 parts by mass of the color former is, for example, 100 parts by mass or more, preferably 200 parts by mass or more, more preferably 300 parts by mass or more, and still more preferably 330 parts by mass or more. The same blending amount is preferably 1000 parts by mass or less, more preferably 700 parts by mass or less, and still more preferably 500 parts by mass or less.

Examples of the color-forming compound (1 st color-forming compound) include leuco dyes, triarylmethane pigments, diphenylmethane pigments, fluoran pigments, spiropyran pigments, and rhodamine pigments. The color former may be used alone or in combination of two or more.

Examples of leuco dyes include 2 '-anilino-6' - (N-ethyl-N-isopentylamino) -3 '-methyl spiro [ tetrachlorophthalide-3, 9' - [9H ] xanthene ], 3-dibutylamino-6-methyl-7-anilinofluoran, 3-dipropylamino-6-methyl-7-anilinofluoran, 3-diethylamino-6-methyl-7-anilinofluoran, 3-dimethylamino-6-methyl-7-anilinofluoran, 3-diethylamino-6-methyl-7-dimethylaminofluoran and 3- (4-diethylamino-2-ethoxyphenyl) -3- (1-ethyl-2-methylindol-3-yl) -4-azaphthalide.

Examples of the triarylmethane dye include p, p', p "-tris (dimethylamino) triphenylmethane. Examples of the diphenylmethane dye include 4, 4-bis-dimethylaminophenyl benzhydryl benzyl ether. Examples of the fluoran dye include 3-diethylamino-6-methyl-7-chlorofluoran. Examples of the spiropyran dye include 3-methyl spiropyran. Examples of rhodamine pigments include rhodamine-B-anilinopactam.

In the pressure-sensitive adhesive layer 10, a leuco dye is preferably used as the color-developing compound, and 2 '-anilino-6' - (N-ethyl-N-isopentylamino) -3 '-methyl spiro [ tetrachlorophthalein-3, 9' - [9H ] xanthene ] is more preferably used.

The amount of the color former to be blended is preferably 0.5 parts by mass or more, more preferably 1 part by mass or more, based on 100 parts by mass of the base polymer. The same blending amount is preferably 10 parts by mass or less, more preferably 7 parts by mass or less.

In the adhesive composition, a photoacid generator having a polymerizable functional group and/or a color former having a polymerizable functional group may be used. For example as described below.

The monomer component forming the base polymer may contain a color former having a polymerizable functional group (color former of the 2 nd type). That is, the color former may be incorporated into the base polymer. Such a color former inhibits movement within the adhesive layer 10.

The polymerizable compound to be compounded with the base polymer in the adhesive composition may contain a color-developing compound having a polymerizable functional group (color-developing compound 2). That is, the color former may be contained in the adhesive composition in a state of being copolymerizable with the polymerizable compound. After the color former is cured by irradiation of the 2 nd active ray (that is, after the polymerization reaction of the polymerizable compound proceeds), the movement in the adhesive layer 10 is suppressed by incorporation into the polymer network.

The monomer component forming the base polymer may contain a color-developing compound having a polymerizable functional group, and the polymerizable compound may contain a color-developing compound having a polymerizable functional group.

These configurations in which the movement of the color former (2 nd color former) is suppressed are suitable for suppressing the diffusion of the color former after color development in the color-change portion 11 formed in the adhesive layer 10, and therefore are suitable for suppressing the deterioration (bleeding, discoloration, unevenness in color appearance, and the like) of the color-change portion 11.

Examples of the 2 nd color former (having a polymerizable functional group) include leuco dyes having a polymerizable functional group, triarylmethane pigments having a polymerizable functional group, diphenylmethane pigments having a polymerizable functional group, fluoranthene pigments having a polymerizable functional group, spiropyran pigments having a polymerizable functional group, and rhodamine pigments having a polymerizable functional group. The polymerizable functional group has an ethylenically unsaturated double bond. Examples of the polymerizable functional group include vinyl, propenyl, and (meth) acryloyl. (meth) acryl means acryl and/or methacryl. Examples of the vinyl group include styryl groups. The 2 nd color former may be used alone or in combination of two or more. As the 2 nd color-developing compound, a leuco dye having a polymerizable functional group is preferably used, a leuco dye having a (meth) acryloyl group is more preferably used, and a leuco dye having an acryloyl group is more preferably used. Examples of the leuco dye having a polymerizable functional group include the leuco dyes containing an acryl group described in international publication No. 2013/048993.

The 2 nd color former may be used together with the 1 st color former or may be used in place of the 1 st color former.

The total amount of the 1 st color former and the 2 nd color former is preferably 0.5 parts by mass or more, more preferably 1 part by mass or more, still more preferably 10 parts by mass or less, still more preferably 7 parts by mass or less, based on 100 parts by mass of the base polymer.

The monomer component forming the base polymer may contain a photoacid generator (2 nd photoacid generator) having a polymerizable functional group. That is, the photoacid generator may be in a state of being incorporated into the base polymer. Such photoacid generator inhibits movement within the adhesive layer 10. Movement of the color former, which develops color by interaction with the acid generated by the photoacid generator, in the adhesive layer 10 is also suppressed.

The polymerizable compound compounded with the base polymer in the adhesive composition may contain a photoacid generator having a polymerizable functional group (2 nd photoacid generator). That is, the photoacid generator may be contained in the adhesive composition in a state of being copolymerizable as the polymerizable compound. Such photoacid generator is incorporated into the polymer network after curing by irradiation with the 2 nd active light (i.e., after polymerization reaction of the polymerizable compound proceeds), and movement within the adhesive layer 10 is suppressed. The movement of the color former compound that develops color by the interaction with the acid generated by such photoacid generator within the adhesive layer 10 is also suppressed.

The monomer component forming the base polymer may contain a photoacid generator having a polymerizable functional group, and the polymerizable compound may contain a photoacid generator having a polymerizable functional group.

These configurations in which the movement of the photoacid generator (2 nd photoacid generator) is suppressed are suitable for suppressing the diffusion of the photoacid generator after color development in the color-change portion 11 formed in the adhesive layer 10, and therefore, are suitable for suppressing the deterioration (bleeding, discoloration, unevenness in color appearance, and the like) of the color-change portion 11.

Examples of the 2 nd photoacid generator include onium compounds that generate acid by ultraviolet irradiation and have polymerizable functional groups. Examples of the polymerizable functional group include the polymerizable functional group described above concerning the 2 nd color former compound. The onium compound is provided, for example, in the form of an onium salt of an onium cation and an anion. Examples of onium cations include iodonium and sulfonium. Examples of the anion include a sulfonic acid derivative anion, a sulfonimide derivative anion, and a sulfonyl methide derivative anion. Preferably the anion has a polymerizable functional group. As the 2 nd photoacid generator, an onium salt of a sulfonic acid derivative anion having a polymerizable functional group and sulfonium is preferably used, an onium salt of a sulfonic acid derivative anion having a (meth) acryloyl group and sulfonium is more preferably used, and triphenylsulfonium/4-vinylbenzenesulfonate is more preferably used. The synthesis of photoacid generators is described, for example, in "Novel polymeric anionic photoacid generators (PAGs) and corresponding polymers for nm lithographic" (Journal of Materials Chemistry,2006, vol.16, p 3701-3707). The 2 nd photo acid generator may be used alone or in combination of two or more.

The 2 nd photo acid generator can be used together with the 1 st photo acid generator or can be used in place of the 1 st photo acid generator.

The amounts of the 1 st photo-acid generator and the 2 nd photo-acid generator are preferably 100 parts by mass or more, more preferably 200 parts by mass or more, still more preferably 300 parts by mass or more, based on 100 parts by mass of the color former. The same amount is preferably 1000 parts by mass or less, more preferably 700 parts by mass or less, and still more preferably 500 parts by mass or less.

The adhesive composition may contain other components as needed. Examples of the other components include silane coupling agents, tackifiers, plasticizers, softeners, antioxidants, surfactants, and antistatic agents.

The adhesive sheet S can be manufactured, for example, as follows: the adhesive composition is applied to a release film (release film 1) to form a coating film, and then the coating film is dried to produce the adhesive composition (in fig. 5, an adhesive sheet S is disposed on a release film L shown by a virtual line).

Examples of the release film include a flexible plastic film. Examples of the plastic film include polyethylene terephthalate film, polyethylene film, polypropylene film and polyester film. The thickness of the release film is, for example, 3 μm or more and, for example, 200 μm or less. The surface of the release film is preferably subjected to a mold release treatment.

Examples of the method for applying the adhesive composition include roll coating, kiss roll coating, gravure coating, reverse roll coating, roll brush, spray coating, dip roll coating, bar coating, blade coating, air knife coating, curtain coating, lip coating, and die coating. The drying temperature of the coating film is, for example, 50 to 200 ℃. The drying time is, for example, 5 seconds to 20 minutes.

When the adhesive composition contains a crosslinking agent, the crosslinking reaction proceeds simultaneously with the drying or by the subsequent aging. Curing conditions are appropriately set according to the type of the crosslinking agent. The curing temperature is, for example, 20℃to 160 ℃. The curing time is, for example, 1 minute to 7 days.

In addition, a release film (release film 2) may be further laminated on the adhesive layer 10 on the release film 1 before or after curing. The 2 nd release film is a flexible plastic film subjected to a surface release treatment, and the same films as those described above for the 1 st release film can be used.

As described above, the pressure-sensitive adhesive sheet S having the pressure-sensitive adhesive surface protected by the release film can be produced. When the pressure-sensitive adhesive sheet S is used, each release film is peeled from the pressure-sensitive adhesive sheet S as necessary.

The thickness of the pressure-sensitive adhesive layer 10 is preferably 10 μm or more, more preferably 15 μm or more, from the viewpoint of ensuring sufficient adhesion to an adherend. From the viewpoint of the handleability of the adhesive sheet S, the thickness of the adhesive layer 10 is preferably 300 μm or less, more preferably 200 μm or less, still more preferably 100 μm or less, and particularly preferably 50 μm or less.

The haze of the adhesive layer 10 is preferably 3% or less, more preferably 2% or less, and still more preferably 1% or less. Such a configuration is suitable for checking the presence or absence of foreign matter and air bubbles between the adhesive sheet S and the adherend after the adhesive sheet S is bonded to the adherend. The haze of the pressure-sensitive adhesive layer 10 can be measured by using a haze meter in accordance with JIS K7136 (year 2000). Examples of the haze meter include "NDH2000" manufactured by Nippon electric color industry Co., ltd., and "HM-150" manufactured by Toku Kogyo Co., ltd.

The average transmittance of the adhesive layer 10 at a wavelength of 400 to 700nm (average transmittance before the irradiation of the adhesive layer 10 with the 1 st active light) is preferably 80% or more, more preferably 85% or more, and still more preferably 90% or more. Such a configuration is suitable for checking the presence or absence of foreign matter and air bubbles between the adhesive sheet S and the adherend after the adhesive sheet S is bonded to the adherend.

The adhesive sheet S is bonded to a glass plate, and then the adhesive force to the stainless steel plate is, for example, 1N/25mm or more and, for example, 50N/25mm or less in peel test under peel conditions of 23 ℃ at a peel angle of 180 DEG and a peel speed of 300 mm/min.

As shown in fig. 2, the pressure-sensitive adhesive sheet S may be a single-sided pressure-sensitive adhesive sheet with a base material including a base material 20 in addition to the pressure-sensitive adhesive layer 10. In this case, the pressure-sensitive adhesive sheet S specifically includes the pressure-sensitive adhesive layer 10 and the base material 20 disposed on one side in the thickness direction thereof. The base material 20 is preferably in contact with one surface in the thickness direction of the adhesive layer 10.

The base material 20 is an element functioning as a transparent support. The base material 20 is, for example, a plastic film having flexibility. Examples of the constituent material of the plastic film include polyolefin, polyester, polyamide, polyimide, polyvinyl chloride, polyvinylidene chloride, cellulose, polystyrene, and polycarbonate. Examples of the polyolefin include polyethylene, polypropylene, poly-1-butene, poly-4-methyl-1-pentene, ethylene/propylene copolymer, ethylene/1-butene copolymer, ethylene/vinyl acetate copolymer, ethylene/ethyl acrylate copolymer and ethylene/vinyl alcohol copolymer. Examples of the polyester include polyethylene terephthalate, polyethylene naphthalate, and polybutylene terephthalate. Examples of the polyamide include polyamide 6,6 and partially aromatic polyamide. In the base material 20, from the viewpoint of both the transparency and the mechanical strength, the plastic material of the base material 20 is preferably polyester, more preferably polyethylene terephthalate.

The substrate 20 has transparency. The haze of the base material 20 is preferably 3% or less, more preferably 2% or less, and further preferably 1% or less. The haze of the substrate 20 can be measured by using a haze meter according to JIS K7136 (year 2000).

The surface of the substrate 20 on the side of the adhesive layer 10 may be subjected to a physical treatment, a chemical treatment, or a primer treatment for improving the adhesion to the adhesive layer 10. Examples of the physical treatment include corona treatment and plasma treatment. Examples of the chemical treatment include an acid treatment and an alkali treatment.

From the viewpoint of securing strength for the base material 20 to function as a support, the thickness of the base material 20 is preferably 5 μm or more, more preferably 10 μm or more, and still more preferably 20 μm or more. In addition, from the viewpoint of achieving moderate flexibility in the pressure-sensitive adhesive sheet S, the thickness of the base material 20 is preferably 200 μm or less, more preferably 150 μm or less, and still more preferably 100 μm or less.

The adhesive sheet S shown in fig. 6 is produced, for example, as follows: the pressure-sensitive adhesive sheet can be produced by the same method as that for producing the pressure-sensitive adhesive sheet described above, except that the base material 20 is used instead of the 1 st release film.

According to the adhesive sheet S shown in fig. 6, the same manufacturing method as that of the adhesive sheet paste described above is performed (in the method for manufacturing the adhesive sheet paste using the adhesive sheet S shown in fig. 6, the base material 20 is disposed instead of the 2 nd member M2) except that the above-described joining step is not performed, referring to fig. 1C. As a result, the adhesive sheet S shown in fig. 6 can produce an adhesive sheet attachment Z' as shown in fig. 7.

The above-described embodiments are examples of the present invention, and the present invention is not limited to the embodiments. Variations of the present invention that are obvious to those skilled in the art are encompassed in the appended claims.

Industrial applicability

The method for producing the adhesive sheet sticker of the present invention can be used, for example, in the production process of a display panel.

Description of the reference numerals

M1 st component 1

M2 nd component

S-adhesive sheet

10 adhesive layer

11 color-changing portion

20 substrate

Z, Z' adhesive sheet adhesive article

Claims (7)

1. A method for producing an adhesive sheet adhesive article, comprising a bonding step of bonding an adhesive sheet to an adherend, wherein the adhesive sheet comprises an adhesive layer which is capable of being discolored and cured by irradiation of the 1 st active ray and is capable of being cured by irradiation of the 2 nd active ray,

the manufacturing method further comprises the following steps: a 1 st curing step of curing the adhesive layer on the adherend by irradiation of the 2 nd active ray to the adhesive layer; and a color change step of forming a color change portion in the adhesive layer by irradiating at least a part of the adhesive layer with the 1 st active light ray further downstream than the 1 st curing step; or alternatively

The manufacturing method further comprises the following steps: a 1 st color-changing curing step of irradiating the adhesive layer on the adherend with the 1 st active light to change the color of the adhesive layer and cure the adhesive layer, or

The manufacturing method further comprises the following steps: a 2 nd color-changing curing step of irradiating the 1 st part of the adhesive layer on the adherend with the 1 st active light to color-change and cure the 1 st part; and a 2 nd curing step of curing the 2 nd portion of the adhesive layer by irradiating the 2 nd active light ray to the 2 nd portion of the adhesive layer further downstream than the discoloration curing step.

2. The method for producing an adhesive sheet attachment according to claim 1, wherein the adhesive layer comprises: a polymerizable compound, a photopolymerization initiator, a compound that develops color by reaction with an acid, and a photoacid generator.

3. The method for producing an adhesive sheet according to claim 2, wherein the adhesive layer has a wavelength range in which the ratio of absorbance Y of the photopolymerization initiator to absorbance X of the photoacid generator is 2 or more in a range of 300nm to 500 nm.

4. The method for producing an adhesive sheet sticker according to claim 1, wherein the 2 nd active light ray in the curing step does not substantially contain light having a wavelength of less than 300 nm.

5. The method for producing an adhesive sheet sticker according to claim 1, wherein in the curing step, as the light source of the 2 nd active light ray, at least one light source selected from the group consisting of a UV-LED lamp, a black light lamp, a high-pressure mercury lamp, and a metal halide lamp is used, and light from the light source is irradiated to the adhesive layer through a wavelength cut filter.

6. The method for producing an adhesive sheet sticker according to claim 1, wherein the 1 st active light ray in the discoloration step and/or the discoloration curing step contains light having a wavelength of less than 300 nm.

7. The method for producing an adhesive sheet sticker according to claim 1, wherein at least one light source selected from the group consisting of a UV-LED lamp, a black light lamp, a high-pressure mercury lamp, and a metal halide lamp is used as the light source of the 1 st active light in the discoloration process and/or the discoloration curing process.

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