JP2019044023A - Adhesive sheet, display body and method for producing display body - Google Patents

Abstract

An adhesive sheet having excellent blister resistance even under severe high-temperature and high-humidity conditions, a display body, and a method for manufacturing a display body. SOLUTION: In a display body in which a display body constituent member 21 and a display body constituent member 22 are bonded with an adhesive sheet provided with an adhesive layer 11 ', at least one of the display body constituent member 21 and the display body constituent member 22 is provided. The pressure-sensitive adhesive layer 11 is made of a plastic plate, and the pressure-sensitive adhesive layer 11 contains a (meth) acrylate polymer (A) containing a monomer having a hydroxyl group in a molecule of 10 to 50% by mass, a crosslinking agent (B), and an active energy ray-curable component ( C) and a photopolymerization initiator (D) having an absorbance at a wavelength of 390 nm in an acetonitrile solution having a concentration of 0.1% by mass of not less than 0.3. A display body 2 which is crosslinked via a crosslinking agent (B) and contains an unreacted active energy ray-curable component (C) and a photopolymerization initiator (D). [Selection diagram] FIG.

Description

  The present invention relates to a pressure-sensitive adhesive sheet suitable for use in a display body (display), a display body obtained by using the pressure-sensitive adhesive sheet, and a method for producing the display body.

  In recent years, car navigation systems are often installed in automobiles. In the display body (display) of the car navigation system, a protective panel is provided on the surface side of the display body module. Usually, the protective panel is bonded to a display module or the like via an adhesive layer.

  As a protective panel for a car navigation system, a plastic plate is often used instead of a glass plate from the viewpoint of safety. However, unlike a glass plate, a plastic plate generates outgas under high temperature and high humidity (humid heat) conditions and permeates water vapor. Thereby, blisters, such as air bubbles, floating, and peeling, may occur between the plastic plate and the adhesive layer.

  Therefore, Patent Document 1 and Patent Document 2 disclose a pressure-sensitive adhesive for a touch panel containing an acrylic polymer containing a predetermined monomer unit from the viewpoint of improving wet heat resistance. However, even when these adhesives are used, the blister resistance, particularly the blister resistance under severe high temperature and high humidity conditions, is not sufficient.

  On the other hand, as an adhesive sheet for a touch panel, Patent Document 3 includes a monomer (meth) acrylic copolymer containing a (meth) acrylic acid ester having an ultraviolet crosslinkable site (benzophenone structure), before and after ultraviolet crosslinking. An ultraviolet crosslinkable pressure-sensitive adhesive sheet having a specified storage elastic modulus is disclosed. Such an ultraviolet-crosslinkable pressure-sensitive adhesive sheet is one that increases the cohesive force by advancing the crosslinking reaction by performing ultraviolet irradiation after bonding the adherend.

JP 2013-1769 A Japanese Patent Laying-Open No. 2015-189852 JP 2011-184582 A

  However, in the ultraviolet crosslinkable pressure sensitive adhesive sheet as described above, the ultraviolet curable pressure sensitive adhesive is not sufficiently cured depending on the type of the protective panel, and blisters may be generated under high temperature and high humidity conditions.

  This invention is made | formed in view of the above actual conditions, and aims at providing the manufacturing method of the adhesive sheet, display body, and display body which are excellent in blister-proof property also on severe high temperature / humidity conditions.

  In order to achieve the above object, first, the present invention provides a pressure-sensitive adhesive sheet comprising a pressure-sensitive adhesive layer for bonding one display member constituting member and another display member constituting member. At least one of the display member constituting member and the other display member constituting member is a plastic plate, and the pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer is a monomer having a hydroxyl group in the molecule as a monomer constituting the polymer. (Meth) acrylic acid ester polymer (A), crosslinking agent (B), active energy ray-curable component (C), and acetonitrile having a concentration of 0.1% by mass It is obtained from an adhesive composition containing a photopolymerization initiator (D) having an absorbance at a wavelength of 390 nm of 0.3 or more in the solution, and the (meth) acrylic acid ester polymer (A) is mutually bonded to the crosslinking agent ( Through B) An active energy ray-curable pressure-sensitive adhesive containing a crosslinked structure formed by crosslinking, an unreacted active energy ray-curable component (C), and the photopolymerization initiator (D). A pressure-sensitive adhesive sheet is provided (Invention 1).

  In the present invention, “consisting of a plastic plate” does not mean “consisting only of a plastic plate”, but allows other layers and members to be laminated on the plastic plate.

  The pressure-sensitive adhesive sheet according to the above invention (invention 1) is a plastic plate, even if at least one of the one display member constituting member and the other display member constituting member to which the pressure-sensitive adhesive layer is bonded is a plastic plate. Even when it contains an ultraviolet absorber, it is excellent in blister resistance under severe high temperature and high humidity conditions, and also excellent in resistance to moist heat whitening.

  In the said invention (invention 1), it is preferable that the said plastic plate contains a ultraviolet absorber (invention 2).

  In the said invention (invention 1 and 2), it is preferable that the gel fraction of the said active energy ray hardening adhesive is 30% or more and 70% or less (invention 3).

  In the said invention (invention 1-3), it is preferable to provide two peeling sheets and the said adhesive layer pinched | interposed into the said peeling sheet so that the peeling surface of the said two peeling sheets may be contact | connected (invention). 4).

  Secondly, the present invention provides a post-curing pressure-sensitive adhesive layer that bonds together one display body constituent member, another display body constituent member, the one display body constituent member, and the other display body constituent member. And at least one of the one display member constituting member and the other display member constituting member is made of a plastic plate, and the post-curing pressure-sensitive adhesive layer is formed of the pressure-sensitive adhesive sheet (Inventions 1 to 4). ) Is a post-curing pressure-sensitive adhesive layer obtained by curing the energy layer with active energy rays (Invention 5).

  In the said invention (invention 5), it is preferable that the gel fraction of the said adhesive layer after hardening is 40% or more and 95% or less (invention 6).

In the above inventions (Inventions 5 and 6), the plastic plate has a water vapor permeability of 0.001 g / (m ² · 24 h) measured according to JIS K7129 under the conditions of 40 ° C. and 90% RH with a thickness of 100 μm. It is preferably made of a material that is 100 μm) or more and 100 g / (m ² · 24 h · 100 μm) or less (Invention 7).

In the said invention (invention 5-7), the water vapor transmission rate measured based on JISK7129 on the conditions of 40 degreeC and 90% RH of said one display body structural member is 0.001 g / (m < ² > * 24h). ), 100 g / (m ² · 24 h) or less, and the water vapor permeability measured in accordance with JIS K7129 under the conditions of 40 ° C. and 90% RH of the other display member constituents is 0.001 g / ( m ² · 24h) or less (Invention 8).

  3rd this invention produces the laminated body formed by bonding one display body structural member and another display body structural member through the adhesive layer of the said adhesive sheet (invention 1-4), An active energy ray is irradiated with respect to the said adhesive layer of the said laminated body, the said adhesive layer is hardened, and the adhesive layer after hardening is provided (invention 9) characterized by the above-mentioned. .

  In the said invention (invention 9), you may irradiate the said adhesive layer to the said adhesive layer through the display body structural member which consists of a plastic plate containing a ultraviolet absorber (invention 10).

  The pressure-sensitive adhesive sheet and display according to the present invention are excellent in blister resistance even under severe high temperature and high humidity conditions. Moreover, according to the manufacturing method of the display body which concerns on this invention, the display body which is excellent in blister-proof property also on severe high temperature / humidity conditions can be manufactured.

It is sectional drawing of the adhesive sheet which concerns on one Embodiment of this invention. It is sectional drawing of the display body which concerns on one Embodiment of this invention.

Hereinafter, embodiments of the present invention will be described.
[Adhesive sheet]
The adhesive sheet which concerns on this embodiment is an adhesive sheet provided with the adhesive layer for bonding one display body structural member and another display body structural member. At least one of the one display member constituting member and the other display member constituting member is made of a plastic plate. A display body and a display body structural member are mentioned later. The pressure-sensitive adhesive sheet according to this embodiment is preferably formed by laminating a release sheet on one or both sides of the pressure-sensitive adhesive layer.

The specific structure as an example of the adhesive sheet which concerns on this embodiment is shown in FIG.
As shown in FIG. 1, the pressure-sensitive adhesive sheet 1 according to an embodiment includes two release sheets 12a and 12b and the two release sheets 12a so as to be in contact with the release surfaces of the two release sheets 12a and 12b. , 12b and an adhesive layer 11 sandwiched between the two layers. In addition, the release surface of the release sheet in this specification refers to a surface having peelability in the release sheet, and includes both a surface that has been subjected to a release treatment and a surface that exhibits peelability without being subjected to a release treatment. .

1. Each member 1-1. Pressure-sensitive adhesive layer The pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer 11 contains 10% by mass or more and 50% by mass or less of a monomer having a hydroxyl group in the molecule (a hydroxyl group-containing monomer) as a monomer constituting the polymer (meta). Light having an absorbance of 0.3 or more at a wavelength of 390 nm in an acrylic acid ester polymer (A), a crosslinking agent (B), an active energy ray-curable component (C), and an acetonitrile solution having a concentration of 0.1% by mass. It is obtained from a pressure-sensitive adhesive composition containing a polymerization initiator (D) (hereinafter sometimes referred to as “pressure-sensitive adhesive composition P”). ), An active energy ray-curable pressure-sensitive adhesive containing a cross-linked structure that is crosslinked via a non-reactive active energy ray-curable component (C) and a photopolymerization initiator (D). The active energy ray-curable pressure-sensitive adhesive is obtained by crosslinking (thermal crosslinking) the pressure-sensitive adhesive composition P, and contains an unreacted active energy ray-curable component (C) and a photopolymerization initiator (D). Therefore, it has active energy ray curability. The active energy ray-curable component (C) is polymerized and cured when the adhesive layer 11 is irradiated with active energy rays when the pressure-sensitive adhesive sheet 1 is used (after bonding the adherend). In the present specification, (meth) acrylic acid means both acrylic acid and methacrylic acid. The same applies to other similar terms. Further, the “polymer” includes the concept of “copolymer”.

  In addition, it is preferable that the active energy ray in this embodiment has light emission of substantial intensity in a wavelength region exceeding the wavelength of 365 nm. The wavelength region is preferably 380 to 450 nm, and more preferably 390 to 410 nm. In addition, when the maximum emission intensity at 365 nm or less (usually having the maximum peak intensity around 365 nm) is 100%, at least a part of the wavelength region has an intensity of 20% or more. It is preferable.

  Since the pressure-sensitive adhesive layer 11 in the pressure-sensitive adhesive sheet 1 according to the present embodiment is relatively soft before curing by active energy ray irradiation, the pressure-sensitive adhesive layer when the pressure-sensitive adhesive sheet 1 is affixed to a display member constituting member having a level difference. 11 easily follows the step, and the occurrence of gaps, floats, etc. in the vicinity of the step is suppressed. Moreover, since the adhesive which comprises the adhesive layer 11 is bridge | crosslinked (thermal crosslinking), and has a certain amount of crosslinking density and predetermined | prescribed cohesion force, the film strength of the adhesive layer 11 is comparatively high. Therefore, for example, the adhesive is prevented from adhering to the blade when the pressure-sensitive adhesive sheet is cut and the adhesive is oozed out of the adhesive layer 11 during storage.

  When using the adhesive sheet 1 which concerns on this embodiment, after bonding one display body structural member and another display body structural member with the adhesive layer 11 of the adhesive sheet 1, one display body structural member or others The active energy ray is irradiated to the pressure-sensitive adhesive layer 11 through the display member constituting member, and the pressure-sensitive adhesive layer 11 is cured to be a pressure-sensitive adhesive layer after curing (the pressure-sensitive adhesive layer 11 ′ after curing in FIG. 2 described later). And

  In the present embodiment, “after curing” of the post-curing pressure-sensitive adhesive layer refers to a state where the increase in the gel fraction of the pressure-sensitive adhesive by irradiation with active energy rays is less than 5 points.

  Here, when the one display member constituting member and / or another display member constituting member (particularly a plastic plate) contains an ultraviolet absorber (usually, the light transmittance at a wavelength of 360 nm is 20% or less, and the wavelength is 390 nm. The light transmittance of 10 nm or more is greater and the light transmittance at a wavelength of 390 nm is larger than the light transmittance at a wavelength of 360 nm.) A conventional photopolymerization initiator such as 1-hydroxycyclohexyl phenyl ketone is used as an adhesive. When used, when the active energy ray is irradiated to the pressure-sensitive adhesive layer through the one display member constituting member or the other display member constituting member, the wavelength (near 360 nm) for cleaving the photopolymerization initiator is used. The active energy ray is absorbed by the ultraviolet absorber in the display member constituting member, and the cleavage of the photopolymerization initiator is inhibited. As a result, the curing reaction of the active energy ray-curable component does not proceed well, and the pressure-sensitive adhesive layer is insufficiently cured. If it does so, blisters, such as a bubble, a float, and peeling, will arise in the interface of the plastic board which generate | occur | produces outgas on high temperature, high humidity conditions, and permeate | transmits water vapor | steam, and an adhesive layer after hardening.

  In contrast, the pressure-sensitive adhesive layer 11 in the pressure-sensitive adhesive sheet 1 according to the present embodiment contains a photopolymerization initiator (D) having an absorbance at a wavelength of 390 nm in an acetonitrile solution having a concentration of 0.1% by mass of 0.3 or more. . In this case, even if the active energy ray is irradiated to the pressure-sensitive adhesive layer 11 through the display member constituting member containing the ultraviolet absorber, the activity of the wavelength (near 390 nm) for cleaving the photopolymerization initiator (D) The energy rays are hardly absorbed by the ultraviolet absorber in the display member constituting member, and the photopolymerization initiator (D) is cleaved without any problem. As a result, the curing reaction of the active energy ray-curable component (C) proceeds favorably, the pressure-sensitive adhesive layer 11 is sufficiently cured, and the cohesive force of the resulting post-curing pressure-sensitive adhesive layer is improved. Moreover, in the adhesive sheet 1 which concerns on this embodiment, a (meth) acrylic acid ester polymer (A) contains a hydroxyl-containing monomer in large quantities as mentioned above as a monomer which comprises the said polymer. Thereby, the glass transition temperature (Tg) of the (meth) acrylic acid ester polymer (A) becomes relatively high. By these actions, even when the laminate (display body) including the plastic plate is placed under severe high temperature and high humidity conditions, for example, 85 ° C. and 85% RH for 1000 hours, the display body constituting member and the post-curing adhesive Generation of blisters at the interface with the layer is suppressed.

  Moreover, in the adhesive sheet 1 which concerns on this embodiment, (meth) acrylic ester polymer (A) is obtained by containing a hydroxyl-containing monomer in a large amount as mentioned above as a monomer which comprises the said polymer. The pressure-sensitive adhesive layer 11 and the post-curing pressure-sensitive adhesive layer exhibit excellent hydrophilicity. Thus, the post-curing pressure-sensitive adhesive layer having excellent hydrophilicity is such that even when the display body 2 is placed under high-temperature and high-humidity conditions, moisture that has entered the pressure-sensitive adhesive layer after curing under the high-temperature and high-humidity conditions is It is presumed that after returning to normal humidity, it will be easy to come off from the adhesive layer after curing. Therefore, even when the plastic plate permeates water vapor under high temperature and high humidity conditions, coupled with the effect of the high glass transition temperature (Tg), the plastic plate and the post-curing pressure-sensitive adhesive layer are caused by the water vapor. Occurrence of floating between the two is suppressed. Moreover, since it becomes difficult to produce | generate condensation of the said water | moisture content in the adhesive layer after hardening because it becomes easy to lose | release water from the adhesive layer after hardening, whitening of the adhesive layer after hardening is suppressed.

  As described above, the pressure-sensitive adhesive sheet 1 according to the present embodiment is such that, even when at least one of the one display member constituting member and the other display member constituting member is a plastic plate, the plastic plate further contains an ultraviolet absorber. Even if it is contained, it is excellent in blister resistance under severe high temperature and high humidity conditions, and is also excellent in moisture and heat whitening resistance.

(1) Component (1-1) (Meth) acrylic acid ester polymer (A)
The (meth) acrylic acid ester polymer (A) contains, as a monomer constituting the polymer, a hydroxyl group-containing monomer of 10% by mass or more, preferably 20% by mass or more, particularly preferably 25% by mass or more. In consideration of the moist heat whitening resistance, it is more preferable to contain 30% by mass or more. Thereby, as above-mentioned, while the adhesive sheet 1 is excellent in blister resistance, it also becomes excellent in moisture-and-heat whitening resistance. In addition, the compatibility with the active energy ray-curable component (C) becomes good, and the transparency of the resulting post-curing pressure-sensitive adhesive layer is improved.

  On the other hand, the (meth) acrylic acid ester polymer (A) contains, as a monomer constituting the polymer, a hydroxyl group-containing monomer of 60% by mass or less, preferably 50% by mass or less, particularly preferably 40% by mass. Contains below. Thereby, it becomes possible to ensure sufficient content of monomers other than a hydroxyl-containing monomer, and the adhesiveness of the obtained adhesive becomes more excellent.

  Examples of the hydroxyl group-containing monomer include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, (meth And (meth) acrylic acid hydroxyalkyl esters such as 3-hydroxybutyl acrylate and 4-hydroxybutyl (meth) acrylate. Of these, 2-hydroxyethyl (meth) acrylate and 4-hydroxybutyl (meth) acrylate are preferred from the viewpoints of blister resistance and wet heat whitening resistance, and in particular, 2-hydroxyethyl acrylate and 2-hydroxymethacrylate. Ethyl is preferred. These may be used alone or in combination of two or more.

  The (meth) acrylic acid ester polymer (A) preferably contains (meth) acrylic acid alkyl ester as a monomer unit constituting the polymer. Thereby, favorable adhesiveness can be expressed. The alkyl group may be linear or branched.

  The (meth) acrylic acid alkyl ester is preferably a (meth) acrylic acid alkyl ester having 1 to 20 carbon atoms in the alkyl group from the viewpoint of adhesiveness. Examples of the (meth) acrylic acid alkyl ester having 1 to 20 carbon atoms in the alkyl group include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, and (meth) acrylic acid n-. Butyl, n-pentyl (meth) acrylate, n-hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isooctyl (meth) acrylate, n-decyl (meth) acrylate, (meth) acrylic acid Examples include n-dodecyl, myristyl (meth) acrylate, palmityl (meth) acrylate, stearyl (meth) acrylate, and the like. These may be used alone or in combination of two or more.

  Among them, (meth) acrylic acid alkyl ester having 2 to 12 carbon atoms in the alkyl group is more preferable and the alkyl group having 5 to 5 carbon atoms from the viewpoint of efficiently imparting adhesive force and blister resistance. Especially preferred are 10 alkyl acrylate esters. Specifically, preferred are butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate and isooctyl (meth) acrylate, and more preferred are 2-ethylhexyl acrylate and isooctyl acrylate. These may be used alone or in combination of two or more.

  The (meth) acrylic acid ester polymer (A) preferably contains 10% by mass or more, and 15% by mass or more, of (meth) acrylic acid alkyl ester as a lower limit as a monomer unit constituting the polymer. It is more preferable to contain 20% by mass or more, and it is more preferable to contain 30% by mass or more. When the lower limit value of the content of the (meth) acrylic acid alkyl ester is as described above, the (meth) acrylic acid ester polymer (A) can exhibit suitable tackiness. Further, the (meth) acrylic acid ester polymer (A) preferably contains 90% by mass or less of an upper limit of (meth) acrylic acid alkyl ester as a monomer unit constituting the polymer, and particularly 85 mass. % Or less, preferably 80% by mass or less. When the upper limit of the content of the (meth) acrylic acid alkyl ester is as described above, a suitable amount of other monomer components such as a hydroxyl group-containing monomer can be introduced into the (meth) acrylic acid ester polymer (A). .

  Moreover, it is preferable that a (meth) acrylic acid ester polymer (A) contains the monomer (alicyclic structure containing monomer) which has an alicyclic structure as a monomer unit which comprises the said polymer. Since the alicyclic structure-containing monomer is bulky, it is presumed that the presence of the alicyclic structure-containing monomer in the polymer increases the distance between the polymers, and the resulting pressure-sensitive adhesive can be made excellent in flexibility. . Thereby, an adhesive becomes what was excellent in level | step difference followable | trackability.

  The carbocyclic ring of the alicyclic structure in the alicyclic structure-containing monomer may have a saturated structure or may have an unsaturated bond in part. The alicyclic structure may be a monocyclic alicyclic structure or a polycyclic alicyclic structure such as a bicyclic ring or a tricyclic ring. From the viewpoint of making the distance between the obtained (meth) acrylic acid ester polymer (A) appropriate and imparting high stress relaxation properties to the pressure-sensitive adhesive, the alicyclic structure is a polycyclic alicyclic structure ( A polycyclic structure). Furthermore, considering the compatibility between the (meth) acrylic acid ester polymer (A) and other components, the polycyclic structure is particularly preferably bicyclic to tetracyclic. In addition, from the viewpoint of imparting stress relaxation properties as described above, the carbon number of the alicyclic structure (refers to the total number of carbon atoms of the portion forming the ring, and when multiple rings exist independently) , Which means the total number of carbon atoms) is usually preferably 5 or more, and particularly preferably 7 or more. On the other hand, the upper limit of the number of carbon atoms in the alicyclic structure is not particularly limited, but it is preferably 15 or less and particularly preferably 10 or less from the viewpoint of compatibility as described above.

  Specific examples of the alicyclic structure-containing monomer include cyclohexyl (meth) acrylate, dicyclopentanyl (meth) acrylate, adamantyl (meth) acrylate, isobornyl (meth) acrylate, and (meth) acrylic. Dicyclopentenyl acid, dicyclopentenyloxyethyl (meth) acrylate, and the like. Among them, dicyclopentanyl (meth) acrylate that exhibits superior blister resistance (carbon number of alicyclic structure: 10), adamantyl (meth) acrylate (carbon number of alicyclic structure: 10) or isobornyl (meth) acrylate (carbon number of alicyclic structure: 7) is preferable, and isobornyl (meth) acrylate is particularly preferable. . These may be used individually by 1 type and may be used in combination of 2 or more type.

  The (meth) acrylic acid ester polymer (A) preferably contains 3% by mass or more, more preferably 6% by mass or more of the alicyclic structure-containing monomer as a monomer unit constituting the polymer. 9% by mass or more is particularly preferable. In addition, the (meth) acrylic acid ester polymer (A) preferably has a content of the alicyclic structure-containing monomer of 30% by mass or less from the viewpoint of securing the blending amount of other components, and is 20% by mass. More preferably, it is more preferably 15% by mass or less. When the proportion of the alicyclic structure-containing monomer is within the above range, the resulting pressure-sensitive adhesive is more excellent in level-step following property and more excellent in adhesive strength to plastic.

  Moreover, it is also preferable that the said (meth) acrylic acid ester polymer (A) contains the monomer which has a nitrogen-containing heterocyclic ring and a (meth) acryloyl group as a monomer unit which comprises the said polymer. By allowing such a monomer to be present in the polymer as a structural unit, the adhesive is given a predetermined polarity, and it has excellent affinity for adherends having a certain degree of polarity such as glass. In addition, the pressure-sensitive adhesive obtained can have an appropriate rigidity.

  Examples of the monomer having a nitrogen-containing heterocyclic ring and a (meth) acryloyl group include N- (meth) acryloylmorpholine, N- (meth) acryloylpyrrolidone, N- (meth) acryloylpiperidine, N- (meth) acryloylpyrrolidine, N- (meth) acryloylaziridine, aziridinylethyl (meth) acrylate and the like can be mentioned. Among them, N- (meth) acryloylmorpholine which exhibits more excellent adhesive strength is preferable, and N-acryloylmorpholine is particularly preferable. These may be used individually by 1 type and may be used in combination of 2 or more type.

  In this embodiment, if a nitrogen atom-containing monomer other than the monomer having a nitrogen-containing heterocyclic ring and a (meth) acryloyl group is used, the cohesive force of the resulting adhesive becomes too high, and initial tack may not be obtained. , Adhesive strength may become excessively low and blister resistance may not be obtained. Therefore, in this embodiment, it is preferable not to use a nitrogen atom-containing monomer other than a monomer having a nitrogen-containing heterocyclic ring and a (meth) acryloyl group.

  When the (meth) acrylic acid ester polymer (A) contains a nitrogen atom-containing monomer as a monomer unit constituting the polymer, the nitrogen atom-containing monomer is preferably contained in an amount of 0.5% by mass or more. The content is preferably 1% by mass or more, and more preferably 3% by mass or more. Further, the (meth) acrylic acid ester polymer (A) preferably contains 20% by mass or less of the nitrogen atom-containing monomer as a monomer unit constituting the polymer, and particularly 15% by mass or less. More preferably, the content is preferably 8% by mass or less. When the content of the nitrogen atom-containing monomer is within the above range, the obtained pressure-sensitive adhesive can sufficiently exhibit excellent adhesion to glass.

  The (meth) acrylic acid ester polymer (A) may contain other monomers as monomer units constituting the polymer, if desired. On the other hand, it is also preferable that the (meth) acrylic acid ester polymer (A) does not contain a carboxy group-containing monomer as a monomer unit constituting the polymer. Since the carboxy group is an acid component, by not containing a carboxy group-containing monomer, there is a problem that causes a defect due to an acid on the adhesive application target, for example, a transparent conductive film such as tin-doped indium oxide (ITO) or a metal film. Even when it exists, those defects (corrosion, resistance value change, etc.) due to the acid can be suppressed.

  Here, “does not contain a carboxy group-containing monomer” means that it contains substantially no carboxy group-containing monomer, and contains no carboxy group-containing monomer at all. It is allowed to contain a carboxy group-containing monomer to such an extent that no corrosion occurs. Specifically, in the (meth) acrylic acid ester polymer (A), as a monomer unit, a carboxy group-containing monomer is 0.1% by mass or less, preferably 0.01% by mass or less, more preferably 0.001. It is allowed to be contained in an amount of mass% or less.

  The (meth) acrylic acid ester polymer (A) is preferably a linear polymer. By being a linear polymer, entanglement of molecular chains is likely to occur, and an improvement in cohesion can be expected, so that a pressure-sensitive adhesive having better blister resistance can be obtained.

  The (meth) acrylic acid ester polymer (A) is preferably a solution polymer obtained by a solution polymerization method. By being a solution polymer, it becomes easy to obtain a high molecular weight polymer, and the resulting pressure-sensitive adhesive can be expected to improve the cohesive force, and therefore has excellent blister resistance.

  The polymerization mode of the (meth) acrylic acid ester polymer (A) may be a random copolymer or a block copolymer.

  The weight average molecular weight of the (meth) acrylic acid ester polymer (A) is preferably 200,000 or more as a lower limit, more preferably 300,000 or more, particularly preferably 400,000 or more, Is preferably 500,000 or more. When the lower limit of the weight average molecular weight of the (meth) acrylic acid ester polymer (A) is not less than the above, the resulting adhesive has more excellent blister resistance.

  The weight average molecular weight of the (meth) acrylic acid ester polymer (A) is preferably 2 million or less as an upper limit, particularly preferably 1.5 million or less, and more preferably 1 million or less. preferable. When the upper limit of the weight average molecular weight of the (meth) acrylic acid ester polymer (A) is not more than the above, the step following property of the pressure-sensitive adhesive obtained is more excellent. In addition, the weight average molecular weight in this specification is the value of standard polystyrene conversion measured by the gel permeation chromatography (GPC) method.

  The glass transition temperature (Tg) of the (meth) acrylic acid ester polymer (A) is preferably −100 ° C. or higher, particularly preferably −60 ° C. or higher, and more preferably −40 ° C. or higher. It is preferable that The glass transition temperature (Tg) is preferably 0 ° C. or lower as an upper limit value, particularly preferably −5 ° C. or lower, and more preferably −10 ° C. or lower. When the glass transition temperature (Tg) of the (meth) acrylic acid ester polymer (A) is in the above range, the resulting pressure-sensitive adhesive has suitable cohesiveness and flexibility, but has sufficient cohesive strength. Thus, the blister resistance and the step following ability are more excellent.

  In the adhesive composition P, the (meth) acrylic acid ester polymer (A) may be used singly or in combination of two or more.

  The content of the (meth) acrylic acid ester polymer (A) in the pressure-sensitive adhesive composition P according to this embodiment is preferably 50% by mass or more, particularly 60% by mass or more, as the lower limit. It is preferable that it is 70 mass% or more. When the lower limit value of the content of the (meth) acrylic acid ester polymer (A) is as described above, the adhesive force of the obtained adhesive becomes better. The content of the (meth) acrylic acid ester polymer (A) is preferably 99% by mass or less, more preferably 97% by mass or less, and particularly 95% by mass or less as an upper limit. It is preferable that it is 93 mass% or less. When the upper limit value of the content of the (meth) acrylic acid ester polymer (A) is as described above, other components such as the crosslinking agent (B), the active energy ray-curable component (C), and the photopolymerization initiator (D) are included. The content of the components is ensured, and the blister resistance is more excellent.

(1-2) Crosslinking agent (B)
The cross-linking agent (B) can cross-link the (meth) acrylic acid ester polymer (A) by heating the pressure-sensitive adhesive composition P and can satisfactorily form a three-dimensional network structure. Thereby, the cohesive force of the obtained adhesive improves more and the blister resistance becomes more excellent.

  As said crosslinking agent (B), what is necessary is just to react with the reactive functional group which (meth) acrylic acid ester polymer (A) has, for example, isocyanate type crosslinking agent, epoxy type crosslinking agent, amine type crosslinking Agent, melamine-based crosslinking agent, aziridine-based crosslinking agent, hydrazine-based crosslinking agent, aldehyde-based crosslinking agent, oxazoline-based crosslinking agent, metal alkoxide-based crosslinking agent, metal chelate-based crosslinking agent, metal salt-based crosslinking agent, ammonium salt-based crosslinking agent Etc. Here, as described above, since the (meth) acrylic acid ester polymer (A) contains a hydroxyl group-containing monomer as a constituent monomer unit, the crosslinking agent (B) is an isocyanate-based crosslinking agent excellent in reactivity with a hydroxyl group. Is preferably used. In addition, a crosslinking agent (B) can be used individually by 1 type or in combination of 2 or more types.

  The isocyanate-based crosslinking agent contains at least a polyisocyanate compound. Examples of the polyisocyanate compound include aromatic polyisocyanates such as tolylene diisocyanate, diphenylmethane diisocyanate and xylylene diisocyanate, aliphatic polyisocyanates such as hexamethylene diisocyanate, alicyclic polyisocyanates such as isophorone diisocyanate and hydrogenated diphenylmethane diisocyanate, etc. , And their biuret bodies, isocyanurate bodies, and adduct bodies that are a reaction product with low molecular active hydrogen-containing compounds such as ethylene glycol, propylene glycol, neopentyl glycol, trimethylolpropane, and castor oil. Among these, trimethylolpropane-modified aromatic polyisocyanate, particularly trimethylolpropane-modified tolylene diisocyanate and trimethylolpropane-modified xylylene diisocyanate are preferable from the viewpoint of reactivity with hydroxyl groups.

  The content of the crosslinking agent (B) in the pressure-sensitive adhesive composition P is preferably 0.01 parts by mass or more with respect to 100 parts by mass of the (meth) acrylic acid ester polymer (A). The amount is preferably 05 parts by mass or more, and more preferably 0.1 parts by mass or more. Further, the content is preferably 3 parts by mass or less, particularly preferably 2 parts by mass or less, and further preferably 1 part by mass or less. When the content of the cross-linking agent (B) is in the above range, the degree of cross-linking becomes appropriate, and the resulting adhesive has more excellent blister resistance.

(1-3) Active energy ray-curable component (C)
When the adhesive composition P contains the active energy ray-curable component (C), the adhesive obtained by crosslinking (thermal crosslinking) the adhesive composition P becomes an active energy ray-curable adhesive. . In this adhesive, the active energy ray-curable components (C) are polymerized to each other by curing by irradiation with active energy rays after the adherend is pasted, and the polymerized active energy ray-curable components (C) are (meth) acrylic. It is presumed that the acid ester polymer (A) is entangled with the crosslinked structure (three-dimensional network structure). The pressure-sensitive adhesive having such a higher-order structure has a high cohesive force and a high film strength, and therefore has a superior blister resistance.

  The active energy ray-curable component (C) is not particularly limited as long as it is a component that is cured by irradiation with active energy rays and can obtain the above-described effects, and may be any of a monomer, an oligomer, or a polymer. It may be a mixture of Among these, a polyfunctional acrylate monomer excellent in compatibility with the (meth) acrylic acid ester polymer (A) and the like can be preferably exemplified.

  Examples of polyfunctional acrylate monomers include 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, and polyethylene glycol di (meth) acrylate. , Neopentyl glycol adipate di (meth) acrylate, hydroxypivalate neopentyl glycol di (meth) acrylate, dicyclopentanyl di (meth) acrylate, caprolactone modified dicyclopentenyl di (meth) acrylate, ethylene oxide modified diphosphate ( (Meth) acrylate, di (acryloxyethyl) isocyanurate, allylated cyclohexyl di (meth) acrylate, ethoxylated bisphenol A diacrylate, 9,9-bis [4- (2-acrylic) Bifunctional type such as yloxyethoxy) phenyl] fluorene; trimethylolpropane tri (meth) acrylate, dipentaerythritol tri (meth) acrylate, propionic acid modified dipentaerythritol tri (meth) acrylate, pentaerythritol tri (meth) acrylate , Trifunctional type such as propylene oxide modified trimethylolpropane tri (meth) acrylate, tris (acryloxyethyl) isocyanurate, ε-caprolactone modified tris- (2- (meth) acryloxyethyl) isocyanurate; Tetrafunctional type such as (meth) acrylate and pentaerythritol tetra (meth) acrylate; pentafunctional type such as propionic acid-modified dipentaerythritol penta (meth) acrylate; dipentaerythritol And hexafunctional types such as hexole (meth) acrylate and caprolactone-modified dipentaerythritol hexa (meth) acrylate. Among these, di (acryloxyethyl) isocyanurate, tris (acryloxyethyl) isocyanurate, and ε-caprolactone-modified tris from the viewpoint of blister resistance of the obtained pressure-sensitive adhesive and step following property under high temperature and high humidity conditions. -A polyfunctional acrylate monomer containing an isocyanurate structure in the molecule, such as-(2- (meth) acryloxyethyl) isocyanurate, is preferred, and a polyfunctional acrylate having a trifunctional or higher functionality and an isocyanurate structure in the molecule Type monomers are more preferable, and ε-caprolactone-modified tris- (2- (meth) acryloxyethyl) isocyanurate is particularly preferable. These may be used individually by 1 type and may be used in combination of 2 or more type. Further, from the viewpoint of compatibility with the (meth) acrylic acid ester polymer (A), the polyfunctional acrylate monomer preferably has a molecular weight of less than 1000.

  As the active energy ray-curable component (C), an active energy ray-curable acrylate oligomer can also be used. Examples of such acrylate oligomers include polyester acrylate, epoxy acrylate, urethane acrylate, polyether acrylate, polybutadiene acrylate, and silicone acrylate.

  The weight average molecular weight of the acrylate oligomer is preferably 50,000 or less, particularly preferably 1,000 to 50,000, and more preferably 3,000 to 40,000. These acrylate oligomers may be used alone or in combination of two or more.

  In addition, as the active energy ray-curable component (C), an adduct acrylate polymer in which a group having a (meth) acryloyl group is introduced into a side chain can also be used. Such an adduct acrylate-based polymer uses a copolymer of (meth) acrylic acid ester and a monomer having a crosslinkable functional group in the molecule, and a part of the crosslinkable functional group of the copolymer. , A (meth) acryloyl group and a compound having a group that reacts with a crosslinkable functional group can be reacted.

  The weight average molecular weight of the adduct acrylate polymer is preferably about 50,000 to 900,000, and particularly preferably about 100,000 to 500,000.

  The active energy ray-curable component (C) can be used by selecting one from the above-mentioned polyfunctional acrylate monomers, acrylate oligomers and adduct acrylate polymers, or a combination of two or more. It can also be used in combination with other active energy ray-curable components.

  The content of the active energy ray-curable component (C) in the pressure-sensitive adhesive composition P is from the viewpoint of improving the cohesive strength of the resulting pressure-sensitive adhesive and having excellent blister resistance. It is preferable that it is 1 mass part or more as a lower limit with respect to 100 mass parts of unification | combination (A), It is more preferable that it is 3 mass parts or more, It is especially preferable that it is 5 mass parts or more. On the other hand, the content is 50 parts by mass or less as an upper limit from the viewpoint of preventing the active energy ray-curable component (C) from phase separation with the (meth) acrylic acid ester polymer (A). Preferably, it is more preferably 20 parts by mass or less, and more preferably 10 parts by mass or less considering the viewpoint of further improving the initial step following ability.

(1-4) Photopolymerization initiator (D)
The photopolymerization initiator (D) in this embodiment has an absorbance at a wavelength of 390 nm in an acetonitrile solution having a concentration of 0.1% by mass of 0.3 or more. Since the pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer 11 contains the photopolymerization initiator (D), when the pressure-sensitive adhesive layer 11 is irradiated with active energy rays through the display member constituting member containing the ultraviolet absorber. However, the photopolymerization initiator (D) is cleaved without problems, and the pressure-sensitive adhesive layer 11 (active energy ray-curable component (C)) is cured well, so that the formed pressure-sensitive adhesive layer is blister resistant. It will be excellent.

  From the above viewpoint, the absorbance at a wavelength of 390 nm of the photopolymerization initiator (D) is preferably 0.5 or more, and particularly preferably 1.0 or more. The upper limit of the absorbance is not particularly limited, but is usually preferably 2.5 or less, and particularly preferably 2.0 or less. When the absorbance exceeds 2.5, the curing reaction of the active energy ray-curable component (C) by the photopolymerization initiator (D) proceeds with ambient light from a fluorescent lamp or the like during the formation or storage of the adhesive sheet. In some cases, the step following capability during subsequent use may be reduced. Here, the measuring method of the light absorbency of a photoinitiator (D) is as showing to the test example mentioned later.

  The photopolymerization initiator (D) preferably has an absorption maximum wavelength of absorbance of 200 to 500 nm in an acetonitrile solution having a concentration of 0.1% by mass of 350 nm or more, particularly preferably 370 nm or more. Is preferably at least 380 nm. When there are a plurality of absorption maximum wavelengths having an absorbance of 200 to 500 nm, at least one absorption maximum wavelength may be in the above range. Thereby, when active energy ray is irradiated to the adhesive layer 11 through the display body structural member containing a ultraviolet absorber, the sclerosis | hardenability of the adhesive layer 11 (active energy ray curable component (C)) is more. The blister resistance is improved. On the other hand, the upper limit value of the absorption maximum wavelength is not particularly limited, but is preferably 450 nm or less, particularly 410 nm or less, from the viewpoint of preventing the progress of the curing reaction when the pressure-sensitive adhesive layer 11 is stored in ambient light. It is preferable that the thickness is 405 nm or less.

  Examples of such a photopolymerization initiator (D) include 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, bis (2 , 4-cyclopentadienyl) bis [2,6-difluoro-3- (1-pyryl) phenyl] titanium (IV). These may be used alone or in combination of two or more.

(1-5) Silane coupling agent (E)
The adhesive composition P preferably further contains a silane coupling agent (E). Thereby, regardless of whether the adherend is a plastic plate or a glass member, the adhesion to the adherend is improved, and the blister resistance is further improved.

  The silane coupling agent (E) is an organosilicon compound having at least one alkoxysilyl group in the molecule, has good compatibility with the (meth) acrylic acid ester polymer (A), and has light transmittance. What has is preferable.

  Examples of the silane coupling agent (E) include polymerizable unsaturated group-containing silicon compounds such as vinyltrimethoxysilane, vinyltriethoxysilane, and methacryloxypropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, Mercapto groups such as silicon compounds having an epoxy structure such as 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 3-mercaptopropyldimethoxymethylsilane Contains amino groups such as silicon compounds, 3-aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane Silicon compound, 3-chloropropyltrimethoxysilane, 3-isocyanatopropyltriethoxysilane, or at least one of them, and alkyl groups such as methyltriethoxysilane, ethyltriethoxysilane, methyltrimethoxysilane, ethyltrimethoxysilane Examples include condensates with silicon compounds. These may be used individually by 1 type and may be used in combination of 2 or more type.

  The content of the silane coupling agent (E) in the adhesive composition P is preferably 0.01 parts by mass or more with respect to 100 parts by mass of the (meth) acrylic acid ester polymer (A), in particular. The amount is preferably 0.05 parts by mass or more, and more preferably 0.1 parts by mass or more. In addition, the content is preferably 1 part by mass or less, particularly preferably 0.5 part by mass or less, and further preferably 0.3 part by mass or less.

(1-6) Various additives For the adhesive composition P, various additives usually used in acrylic pressure-sensitive adhesives, for example, an ultraviolet absorber, an antistatic agent, a tackifier, an antioxidant, if desired. Light stabilizers, softeners, fillers, refractive index adjusters, rust inhibitors and the like can be added. In addition, the below-mentioned polymerization solvent and dilution solvent shall not be contained in the additive which comprises the adhesive composition P.

(2) Manufacture of adhesive composition The adhesive composition P manufactured the (meth) acrylic acid ester polymer (A), the obtained (meth) acrylic acid ester polymer (A), and a crosslinking agent ( B), the active energy ray-curable component (C), and the photopolymerization initiator (D) can be mixed and optionally added by adding a silane coupling agent (E) and an additive. .

  The (meth) acrylic acid ester polymer (A) can be produced by polymerizing a mixture of monomers constituting the polymer by an ordinary radical polymerization method. The polymerization of the (meth) acrylic acid ester polymer (A) can be performed by a solution polymerization method or the like using a polymerization initiator as desired. Examples of the polymerization solvent include ethyl acetate, n-butyl acetate, isobutyl acetate, toluene, acetone, hexane, methyl ethyl ketone, and the like. Two or more kinds may be used in combination.

  Examples of the polymerization initiator include azo compounds and organic peroxides, and two or more kinds may be used in combination. Examples of the azo compound include 2,2′-azobisisobutyronitrile, 2,2′-azobis (2-methylbutyronitrile), 1,1′-azobis (cyclohexane 1-carbonitrile), 2 2,2′-azobis (2,4-dimethylvaleronitrile), 2,2′-azobis (2,4-dimethyl-4-methoxyvaleronitrile), dimethyl 2,2′-azobis (2-methylpropionate) 4,4′-azobis (4-cyanovaleric acid), 2,2′-azobis (2-hydroxymethylpropionitrile), 2,2′-azobis [2- (2-imidazolin-2-yl) Propane] and the like.

  Examples of organic peroxides include benzoyl peroxide, t-butyl perbenzoate, cumene hydroperoxide, diisopropyl peroxydicarbonate, di-n-propyl peroxydicarbonate, and di (2-ethoxyethyl) peroxy. Examples include dicarbonate, t-butyl peroxyneodecanoate, t-butyl peroxybivalate, (3,5,5-trimethylhexanoyl) peroxide, dipropionyl peroxide, diacetyl peroxide and the like.

  In addition, in the said superposition | polymerization process, the weight average molecular weight of the polymer obtained can be adjusted by mix | blending chain transfer agents, such as 2-mercaptoethanol.

  Once the (meth) acrylic acid ester polymer (A) is obtained, the solution of the (meth) acrylic acid ester polymer (A) is added to the crosslinking agent (B), the active energy ray-curable component (C), and photopolymerization is started. The adhesive composition P (coating solution) diluted with a solvent can be obtained by adding the agent (D) and, if desired, the silane coupling agent (E) and additives and mixing them well. When any of the above components is used in a solid state or when precipitation occurs when mixed with other components in an undiluted state, the component is used alone as a dilution solvent. It may be dissolved or diluted and then mixed with other components.

  Examples of the dilution solvent include aliphatic hydrocarbons such as hexane, heptane, and cyclohexane, aromatic hydrocarbons such as toluene and xylene, halogenated hydrocarbons such as methylene chloride and ethylene chloride, methanol, ethanol, propanol, butanol, Alcohols such as 1-methoxy-2-propanol, ketones such as acetone, methyl ethyl ketone, 2-pentanone, isophorone, and cyclohexanone, esters such as ethyl acetate and butyl acetate, and cellosolve solvents such as ethyl cellosolve are used.

  The concentration / viscosity of the coating solution thus prepared is not particularly limited as long as it can be coated, and can be appropriately selected depending on the situation. For example, it dilutes so that the density | concentration of the adhesive composition P may be 10-60 mass%. In addition, when obtaining a coating solution, addition of a dilution solvent etc. is not a necessary condition, and if a viscosity etc. which can be coated with the adhesive composition P are not necessary, a dilution solvent does not need to be added. In this case, the adhesive composition P becomes a coating solution using the polymerization solvent of the (meth) acrylic acid ester polymer (A) as a dilution solvent.

(3) Formation of pressure-sensitive adhesive layer The pressure-sensitive adhesive layer 11 is obtained by thermally crosslinking the pressure-sensitive adhesive composition P. That is, the adhesive composition P is crosslinked by heat treatment. In addition, this heat processing can also serve as the drying process after application | coating of the adhesive composition P. FIG.

  The heating temperature of the heat treatment is preferably 50 to 150 ° C, and particularly preferably 70 to 120 ° C. The heating time is preferably 10 seconds to 10 minutes, particularly preferably 50 seconds to 2 minutes. Furthermore, it is particularly preferable to provide a curing period of about 1 to 2 weeks at room temperature (for example, 23 ° C., 50% RH) after the heat treatment.

  By the heat treatment (and curing), the (meth) acrylic acid ester polymer (A) is well crosslinked through the crosslinking agent (B).

(4) Thickness of the pressure-sensitive adhesive layer The thickness of the pressure-sensitive adhesive layer 11 (value measured according to JIS K7130) is preferably 20 μm or more as a lower limit, more preferably 25 μm or more, and particularly 30 μm. It is preferable that it is above, and it is more preferable that it is 50 micrometers or more. The thickness of the pressure-sensitive adhesive layer 11 is preferably 500 μm or less as an upper limit, more preferably 400 μm or less, and particularly preferably 300 μm or less. When the thickness of the pressure-sensitive adhesive layer 11 is in the above range, it is more excellent in blister resistance. Moreover, when the lower limit value of the thickness of the pressure-sensitive adhesive layer 11 is as described above, the moisture and heat whitening resistance is further improved.

1-2. Release sheet The release sheets 12a and 12b protect the adhesive layer 11 until the adhesive sheet 1 is used, and are released when the adhesive sheet 1 (adhesive layer 11) is used. In the pressure-sensitive adhesive sheet 1 according to this embodiment, one or both of the release sheets 12a and 12b are not necessarily required.

  Examples of the release sheets 12a and 12b include polyethylene film, polypropylene film, polybutene film, polybutadiene film, polymethylpentene film, polyvinyl chloride film, vinyl chloride copolymer film, polyethylene terephthalate film, polyethylene naphthalate film, and polybutylene. Terephthalate film, polyurethane film, ethylene vinyl acetate film, ionomer resin film, ethylene / (meth) acrylic acid copolymer film, ethylene / (meth) acrylic acid ester copolymer film, polystyrene film, polycarbonate film, polyimide film, fluorine A resin film or the like is used. These crosslinked films are also used. Furthermore, these laminated films may be sufficient.

  It is preferable that the peeling surface (especially the surface in contact with the pressure-sensitive adhesive layer 11) of the release sheets 12a and 12b is subjected to a peeling treatment. Examples of the release agent used for the release treatment include alkyd, silicone, fluorine, unsaturated polyester, polyolefin, and wax release agents. Of the release sheets 12a and 12b, one release sheet is preferably a heavy release release sheet having a high release force, and the other release sheet is preferably a light release release sheet having a low release force.

  Although there is no restriction | limiting in particular about the thickness of release sheet 12a, 12b, Usually, it is about 20-150 micrometers.

2. Manufacture of an adhesive sheet As one manufacture example of the adhesive sheet 1, the coating liquid of the said adhesive composition P is apply | coated to the peeling surface of one peeling sheet 12a (or 12b), it heat-processes, and an adhesive composition is performed. After P is crosslinked (thermally crosslinked) to form an application layer, the release surface of the other release sheet 12b (or 12a) is superimposed on the application layer. When a curing period is required, a curing period is set, and when the curing period is unnecessary, the coating layer becomes the pressure-sensitive adhesive layer 11 as it is. Thereby, the said adhesive sheet 1 is obtained. The conditions for the heat treatment and curing are as described above.

  As another production example of the pressure-sensitive adhesive sheet 1, a coating solution of the pressure-sensitive adhesive composition P is applied to the release surface of one release sheet 12a, and heat treatment is performed to cross-link the pressure-sensitive adhesive composition P (thermal crosslinking). Then, a coating layer is formed to obtain a release sheet 12a with a coating layer. Moreover, the application solution of the adhesive composition P is applied to the release surface of the other release sheet 12b, and heat treatment is performed to crosslink (thermally crosslink) the adhesive composition P to form an application layer. A release sheet 12b with a coating layer is obtained. And the peeling sheet 12a with an application layer and the peeling sheet 12b with an application layer are bonded together so that both application layers may mutually contact. When the curing period is necessary, the curing period is set, and when the curing period is unnecessary, the above-mentioned laminated application layer becomes the pressure-sensitive adhesive layer 11 as it is. Thereby, the said adhesive sheet 1 is obtained. According to this production example, even when the pressure-sensitive adhesive layer 11 is thick, it can be stably produced.

  For example, a bar coating method, a knife coating method, a roll coating method, a blade coating method, a die coating method, or a gravure coating method can be used as a method for applying the coating solution of the adhesive composition P.

3. Physical Properties of Adhesive Sheet (1) Water Vapor Permeability In the adhesive sheet 1 according to the present embodiment, a post-curing adhesive layer obtained by curing an adhesive layer 11 having a thickness of 100 μm by irradiation with active energy rays is used as two Tetrons. It is preferable that the water vapor permeability of the pressure-sensitive adhesive layer after curing is 108 g / (m ² · 24h · 100 µm) or more measured by compliant with JIS K7129 between 40 ° C and 90% RH. In particular, it is preferably 110 g / (m ² · 24h · 100 µm) or more, and more preferably 115 g / (m ² · 24h · 100 µm) or more. The water vapor permeability is preferably 200 g / (m ² · 24 h · 100 μm) or less, more preferably 180 g / (m ² · 24 h · 100 μm) or less, particularly 160 g / (m ² · 24 h · 100 μm) or less, more preferably 150 g / (m ² · 24 h · 100 μm) or less. The water vapor permeability test method is as shown in the test examples described later.

  In the pressure-sensitive adhesive sheet 1 according to the present embodiment, the water vapor permeability of the post-curing pressure-sensitive adhesive layer is in the above range, so that the blister resistance is more excellent when the display body is placed under high temperature and high humidity conditions. In addition, the whitening of the post-curing pressure-sensitive adhesive layer is more effectively suppressed when the display returns to room temperature and normal humidity after being placed under high temperature and high humidity conditions.

(2) Gel fraction (2-1) Gel fraction before active energy ray irradiation The gel fraction of the pressure-sensitive adhesive (before active energy ray irradiation) constituting the pressure-sensitive adhesive layer 11 is 30% or more as the lower limit. Preferably, it is 40% or more, more preferably 50% or more. When the lower limit of the gel fraction of the pressure-sensitive adhesive before irradiation with active energy rays is as described above, the cohesive force of the pressure-sensitive adhesive layer 11 is improved, and the pressure-sensitive adhesive adheres to the blade when the pressure-sensitive adhesive sheet 1 is cut. It is possible to effectively suppress the pressure-sensitive adhesive from oozing out from the pressure-sensitive adhesive layer 11 during storage. Further, the gel fraction of the pressure-sensitive adhesive before irradiation with active energy rays is preferably 70% or less as an upper limit, particularly preferably 65% or less, and further preferably 60% or less. When the upper limit value of the gel fraction of the pressure-sensitive adhesive before irradiation with active energy rays is as described above, the pressure-sensitive adhesive does not become too hard, and the initial step followability becomes more excellent. The measuring method of the gel fraction of this adhesive (before irradiation with active energy rays) is as shown in the test examples described later.

(2-2) Gel fraction after irradiation with active energy rays The gel fraction of the adhesive constituting the post-curing adhesive layer formed by irradiating the adhesive layer 11 with active energy rays is 60% or more as a lower limit. In particular, it is preferably 62% or more, and more preferably 65% or more. When the lower limit of the gel fraction is the above, the cohesive force of the pressure-sensitive adhesive constituting the post-curing pressure-sensitive adhesive layer becomes sufficient, and more excellent blister resistance can be exhibited. Further, the gel fraction of the pressure-sensitive adhesive constituting the post-curing pressure-sensitive adhesive layer is preferably 95% or less as an upper limit, particularly preferably 90% or less, and more preferably 80% or less. . When the upper limit of the gel fraction is as described above, the adhesive strength of the post-curing pressure-sensitive adhesive layer can be secured and sufficient durability can be obtained. The method for measuring the gel fraction of the pressure-sensitive adhesive (after irradiation with active energy rays) constituting the post-curing pressure-sensitive adhesive layer is as shown in the test examples described later.

(2-3) Change amount of gel fraction Change amount of gel fraction accompanying hardening by active energy ray irradiation of the active energy ray-curable pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer 11 (to constitute a pressure-sensitive adhesive layer after curing) The value obtained by subtracting the gel fraction of the active energy ray-curable adhesive from the gel fraction of the adhesive is preferably 5 points or more, particularly preferably 10 points or more, and more preferably 15 points or more. It is preferable that As the gel fraction increases in this way, the obtained post-curing pressure-sensitive adhesive layer becomes more excellent in blister resistance. The upper limit of the increase in the gel fraction is not particularly limited, but from the viewpoint of preventing the pressure-sensitive adhesive layer from becoming too hard after curing, the increase in the gel fraction is preferably 40 points or less. 30 points or less is more preferable, and 25 points or less is particularly preferable.

(3) Moisture and heat whitening resistance The moisture and heat whitening resistance of the pressure-sensitive adhesive according to the present embodiment can be quantitatively evaluated by the haze value as shown below.

  That is, the pressure-sensitive adhesive layer 11 having a thickness of 50 μm is applied to a glass plate and a plastic plate having a thickness of 0.7 mm (a plastic plate in which a polymethyl methacrylate resin layer is laminated on a polycarbonate resin plate; the polycarbonate resin plate is the pressure-sensitive adhesive layer side). In the laminated body sandwiched between the layers, the adhesive layer 11 is cured by irradiation with active energy rays to form a cured adhesive layer, and the laminated body is subjected to 1000 hours under a wet heat condition of 85 ° C. and 85% RH. A storage durability test was conducted, and then a haze value (measured in accordance with JIS K7136: 2000) when stored at 23 ° C. and 50% RH at room temperature and normal humidity for 24 hours. The value (point) after subtracting is preferably less than 1.5, particularly preferably less than 1.2, and more preferably less than 1.0. It is preferred.

  In addition, the adhesive layer 11 having a thickness of 250 μm, a glass plate and a plastic plate having a thickness of 0.7 mm (a plastic plate in which a polymethyl methacrylate resin layer is laminated on a polycarbonate resin plate; the polycarbonate resin plate is the adhesive layer side) In the laminated body sandwiched between the layers, the adhesive layer 11 is cured by irradiation with active energy rays to form a cured adhesive layer, and the laminated body is subjected to 1000 hours under a wet heat condition of 85 ° C. and 85% RH. A storage endurance test was performed, and then the value (point) obtained by subtracting the haze value before the endurance test from the haze value when stored at room temperature and humidity of 23 ° C. and 50% RH for 24 hours was less than 1.0. Preferably, it is less than 0.7, preferably less than 0.5, more preferably less than 0.3.

  In addition, the adhesive layer 11 having a thickness of 50 μm, a glass plate and a plastic plate having a thickness of 2.0 mm (a plastic plate in which a polymethyl methacrylate resin layer is laminated on a polycarbonate resin plate; the polycarbonate resin plate is the adhesive layer side) In the laminated body sandwiched between the layers, the adhesive layer 11 is cured by irradiation with active energy rays to form a cured adhesive layer, and the laminated body is subjected to 1000 hours under a wet heat condition of 85 ° C. and 85% RH. The value (point) obtained by subtracting the haze value before the endurance test from the haze value when the endurance test to be stored is performed and then stored at 23 ° C. and 50% RH at normal temperature and humidity for 24 hours is less than 8. Is particularly preferable, and is preferably less than 5, more preferably less than 1.5.

  Furthermore, the adhesive layer 11 having a thickness of 250 μm is formed of a glass plate and a plastic plate having a thickness of 2.0 mm (a plastic plate in which a polymethyl methacrylate resin layer is laminated on a polycarbonate resin plate; the polycarbonate resin plate is the adhesive layer side). In the laminated body sandwiched between the layers, the adhesive layer 11 is cured by irradiation with active energy rays to form a cured adhesive layer, and the laminated body is subjected to 1000 hours under a wet heat condition of 85 ° C. and 85% RH. The value (point) obtained by subtracting the haze value before the endurance test from the haze value when the endurance test to be stored is performed and then stored at 23 ° C. and 50% RH at normal temperature and humidity for 24 hours is less than 8. Is preferably less than 6, particularly preferably less than 3, and even more preferably less than 1.

  When the above-described difference in haze value is in the above range, it can be said that the increase in haze value is small even after being placed under wet heat conditions, and whitening of the adhesive is suppressed. In addition, the plastic plate, particularly the plastic plate having the above-described configuration, is relatively easy to transmit moisture under wet heat conditions. Therefore, in a laminate in which a general post-curing pressure-sensitive adhesive layer is sandwiched between a glass plate and a plastic plate, moisture permeates the plastic plate under wet heat conditions, and the water easily reaches the post-curing pressure-sensitive adhesive layer. . Therefore, in such a laminated body, compared with the laminated body which pinched | interposed the adhesive layer between the two glass plates generally, the adhesive layer after hardening is easy to whiten. However, according to the pressure-sensitive adhesive sheet 1 according to the present embodiment, excellent moisture and heat whitening resistance is exhibited even in the above laminate. In addition, the test method about moisture-and-heat whitening resistance mentioned above is as showing to the test example mentioned later.

(4) Haze value In the pressure-sensitive adhesive sheet 1 according to this embodiment, the haze value of the pressure-sensitive adhesive layer 11 is preferably 5% or less, more preferably 3% or less, and particularly preferably 1% or less. Is preferable, and it is preferable that it is 0.5% or less. When the haze value of the pressure-sensitive adhesive layer 11 is 5% or less, the transparency is very high, which is suitable for optical applications (for display bodies). In addition, the haze value of the adhesive layer 11 does not change even after curing by irradiation with active energy rays.

(5) Step-following rate In the pressure-sensitive adhesive sheet 1 according to the present embodiment, the step-following rate (%) represented by the following formula in the post-curing pressure-sensitive adhesive layer obtained by curing the pressure-sensitive adhesive layer 11 by irradiation with active energy rays. However, the lower limit is preferably 5% or more, more preferably 10% or more, particularly preferably 15% or more, and further preferably 20% or more. Further, the upper limit value of the step following rate is not particularly limited, but is usually preferably 80% or less, and particularly preferably 70% or less. In addition, the test method of a level | step difference tracking rate is as showing to the test example mentioned later.
Step follow-up rate (%) = {(the height of the step (μm) in which the buried state is maintained without bubbles, floats, peeling, etc. after a predetermined durability test) / (thickness of the adhesive layer)} × 100

  When the step following rate of the pressure-sensitive adhesive layer after curing is in the above range, the pressure-sensitive adhesive layer after curing favorably follows the step of the display member constituent member even through the durability test, and bubbles, floats in the vicinity of the step, Occurrence of peeling or the like is suppressed, thereby suppressing occurrence of light reflection loss. As a result, it is possible to manufacture a display body having better image quality.

(6) Adhesive strength When the adhesive layer 11 of the adhesive sheet 1 according to the present embodiment is cured by irradiation with active energy rays to form a post-cured adhesive layer, the adhesive strength of the adhesive sheet 1 to soda lime glass is The lower limit is preferably 20 N / 25 mm or more, particularly preferably 25 N / 25 mm or more, and more preferably 30 N / 25 mm or more. When the adhesive strength of the pressure-sensitive adhesive sheet 1 is 20 N / 25 mm or more, the blister resistance is more excellent. On the other hand, the upper limit value of the adhesive strength is not particularly limited, but it is usually preferably 100 N / 25 mm or less, more preferably 90 N / 25 mm or less, and particularly preferably 80 N / 25 mm or less. In addition, the said adhesive force says the adhesive force measured by the 180 degree | times peeling method according to JISZ0237: 2009 fundamentally, and the specific test method is as showing in the test example mentioned later.

4). Use of pressure-sensitive adhesive sheet A preferred use example of the pressure-sensitive adhesive sheet 1 according to this embodiment will be described. One display body constituent member and another display body constituent member are bonded together by the active energy ray-curable adhesive layer 11 of the adhesive sheet 1. At least one of the one display member constituting member and the other display member constituting member is an ultraviolet shielding member. Then, the adhesive layer 11 is irradiated with active energy rays through the display member constituting member which is the ultraviolet shielding member, and the pressure-sensitive adhesive layer 11 is cured to be a cured pressure-sensitive adhesive layer (post-cured pressure-sensitive adhesive layer 11). ').

  The ultraviolet shielding member has a light transmittance at a wavelength of 360 nm of 20% or less, a light transmittance at a wavelength of 390 nm of 10% or more, and a light transmittance at a wavelength of 390 nm is a light transmittance at a wavelength of 360 nm. Is bigger than that.

[Display]
The pressure-sensitive adhesive sheet 1 according to this embodiment can be used for manufacturing a display body 2 as exemplified in FIG. As shown in FIG. 2, the display body 2 according to this embodiment includes a first display body constituent member 21 (one display body constituent member) having a step on at least a surface to be bonded, and a second display body. The display body constituent member 22 (other display body constituent member) and the post-curing pressure-sensitive adhesive layer 11 which is located between them and bonds the first display body constituent member 21 and the second display body constituent member 22 to each other. 'And configured with. In the display body 2 according to the present embodiment, the first display body constituting member 21 has a step on the post-curing pressure-sensitive adhesive layer 11 ′ side surface or the pressure-sensitive adhesive layer 11 side surface, specifically, Although there is a step due to the printing layer 3, it is not limited to this.

  Here, when one display body constituent member (for example, the first display body constituent member 21) is an ultraviolet shielding member, the other display body constituent member (for example, the second display body constituent member 22) is irradiated with ultraviolet rays. A member whose performance is deteriorated or a member having a structure in which the active energy ray cannot be irradiated to the pressure-sensitive adhesive layer 11 from the other display member constituting member side is preferable. Even when a member having such restrictions is used for the display member constituting member, if the adhesive sheet 1 according to the above-described embodiment is used, by irradiating the active energy ray from the ultraviolet shielding member side, The pressure-sensitive adhesive layer 11 is sufficiently cured to become a pressure-sensitive adhesive layer 11 ′ after curing, and the display body 2 excellent in blister resistance can be obtained even under severe high temperature and high humidity conditions.

  The post-curing pressure-sensitive adhesive layer 11 ′ included in the display body 2 is obtained by curing the pressure-sensitive adhesive layer 11 of the pressure-sensitive adhesive sheet 1 described above by irradiation with active energy rays. The pressure-sensitive adhesive constituting the post-curing pressure-sensitive adhesive layer 11 ′ has a crosslinked structure composed of the (meth) acrylic acid ester polymer (A) and the crosslinking agent (B), and an active energy ray-curable component ( It contains a cured product (polymer) of C), and may further contain a photopolymerization initiator (D) and an additive, if desired. In this case, the polymerized active energy ray-curable component (C) is entangled with the crosslinked structure composed of the (meth) acrylic acid ester polymer (A) and the crosslinking agent (B) to form a higher order structure. It is estimated that

  In addition, the photoinitiator (D) contained in the adhesive which comprises the said adhesive layer 11 'after hardening is the photoinitiator (D) contained in the adhesive composition P is active energy ray irradiation. It remains without being cleaved. Therefore, the content thereof is not large, and is usually 0.0001% by mass or more and 0.1% by mass or less, preferably 0.0001% by mass or more and 0.01% by mass or less in the pressure-sensitive adhesive. .

  In the display body 2 according to the present embodiment, at least one of the first display body constituting member 21 and the second display body constituting member 22 is made of a plastic plate. Here, the plastic plate usually tends to transmit water vapor when placed under high temperature and high humidity conditions, for example, 85 ° C. and 85% RH. Therefore, there is a possibility that blisters such as bubbles, floats, and peeling occur at the interface between the plastic plate and the cured adhesive layer 11 ′ due to the water vapor, and the cured adhesive layer 11 ′ may be whitened. Come. However, even if the display body 2 according to the present embodiment includes such a plastic plate, the post-curing pressure-sensitive adhesive layer 11 ′ is derived from the pressure-sensitive adhesive sheet 1 according to the present embodiment, so that blister Generation or whitening of the post-curing pressure-sensitive adhesive layer 11 ′ can be satisfactorily suppressed.

  The plastic plate is not particularly limited. For example, an acrylic resin plate such as a polycarbonate resin (PC) plate or a polymethyl methacrylate resin (PMMA) plate, or an acrylic resin such as a polymethyl methacrylate resin layer on the polycarbonate resin plate. For example, a plastic plate laminated with layers. In addition, said polycarbonate resin board may contain resin other than polycarbonate resin as a material which comprises it, and said acrylic resin board contains resin other than an acrylic resin as a material which comprises it. You may contain.

  Although the thickness of a plastic board is not specifically limited, Usually, it is 0.2-5 mm, Preferably it is 0.4-3 mm, Most preferably, it is 0.6-2.5 mm, More preferably, it is 1- 2.1 mm.

  Moreover, the plastic plate may contain the ultraviolet absorber. Since the adhesive layer 11 contains a photopolymerization initiator (D) having an absorbance at a wavelength of 390 nm of 0.3 or more, the adhesive layer 11 is irradiated with active energy rays through a plastic plate containing an ultraviolet absorber. Even so, the pressure-sensitive adhesive layer 11 is sufficiently cured, and a post-curing pressure-sensitive adhesive layer 11 ′ having a high cohesive force is obtained. Thereby, even when the display body 2 is left under a high temperature and high humidity condition for a long time, the generation of blisters at the interface between the plastic plate and the post-curing adhesive layer 11 ′ is suppressed.

In the display body 2 according to the present embodiment, at least one of the first display body constituting member 21 and the second display body constituting member 22 is 40 μC and 90% RH as a thickness of 100 μm in the material constituting the plastic plate. The water vapor permeability measured in accordance with JIS K7129 under conditions is preferably 0.001 g / (m ² · 24h · 100 µm) or more, particularly 0.01 g / (m ² · 24h · 100 µm) or more. In particular, it is preferably 0.05 g / (m ² · 24h · 100 µm) or more. The water vapor permeability is preferably 100 g / (m ² · 24h · 100 µm) or less, particularly preferably 95 g / (m ² · 24h · 100 µm) or less, and more preferably 85 g / (m ^2). It is preferably 24 h · 100 μm) or less. Even if the plastic plate is made of a material having the above water vapor permeability and easily allows moisture to pass therethrough, the post-curing pressure-sensitive adhesive layer 11 ′ is derived from the pressure-sensitive adhesive sheet 1 according to this embodiment, so that blister Generation or whitening of the post-curing pressure-sensitive adhesive layer 11 ′ can be satisfactorily suppressed.

In addition, the water vapor permeability of the material constituting the plastic plate described above is the water vapor permeability of the plastic plate made of the material using a permeability measuring device in accordance with JIS K7129 under the conditions of 40 ° C. and 90% RH. After measuring (actually measured value), it is obtained by converting the measurement result into a thickness of 100 μm of the plastic plate using the following calculation formula.
Water vapor transmission rate (g / (m ² · 24h · 100 µm)) = Water vapor transmission rate (actual measured value) × (actual thickness of plastic plate / 100)

  It is preferable that the 1st display body structural member 21 is a protection panel which consists of a plastic plate mentioned above, and it is preferable that the said plastic plate contains a ultraviolet absorber. In this case, the display body 2 is excellent in light resistance, and even if the display body 2 after manufacture is exposed to ultraviolet rays from the first display body constituting member 21 side, the post-curing pressure-sensitive adhesive layer 11 ′ and Deterioration of the second display member constituting member 22 in the lower layer is suppressed. In particular, in the post-curing pressure-sensitive adhesive layer 11 ', excellent blister resistance is maintained well.

  Even if various functional layers (transparent conductive film, metal layer, silica layer, hard coat layer, antiglare layer, etc.) are provided on one side or both sides of the plastic plate constituting the first display member constituting member 21. The optical member may be laminated. Moreover, the transparent conductive film and the metal layer may be patterned.

  The second display member constituting member 22 may be a glass plate, an optical member to be attached to the first display member constituting member 21, a display member module (for example, a liquid crystal (LCD) module, a light emitting diode ( LED) module, organic electroluminescence (organic EL) module, etc.), an optical member as a part of the display module, or a laminate including the display module. These optical members, display module, laminate, etc. may be provided with a glass plate.

  The glass plate is not particularly limited. For example, chemically tempered glass, alkali-free glass, quartz glass, soda lime glass, barium / strontium-containing glass, aluminosilicate glass, lead glass, borosilicate glass, barium borosilicate Glass etc. are mentioned. Although the thickness of a glass plate is not specifically limited, Usually, it is 0.1-10 mm, Preferably it is 0.2-5 mm, More preferably, it is 0.8-2 mm.

  Even if various functional layers (transparent conductive film, metal layer, silica layer, hard coat layer, antiglare layer, etc.) are provided on one or both surfaces of the glass plate constituting the second display member constituting member 22. The optical member may be laminated. Moreover, the transparent conductive film and the metal layer may be patterned.

  Examples of the optical member include a scattering prevention film, a polarizing plate (polarizing film), a polarizer, a retardation plate (retarding film), a viewing angle compensation film, a brightness enhancement film, a contrast enhancement film, a liquid crystal polymer film, and a diffusion film. , Transflective film, transparent conductive film, and the like. Examples of the scattering prevention film include a hard coat film in which a hard coat layer is formed on one side of a base film. The optical member may contain an ultraviolet absorber.

  Further, the second display member constituting member 22 is a member whose performance is deteriorated by ultraviolet irradiation, or an active energy ray from the second display member constituting member 22 side to the active energy ray-curable adhesive layer 11. It is preferable that the member has a structure that cannot be irradiated. Specifically, it is preferable that the 2nd display body structural member 22 is a laminated body containing a display body module or a display body module.

  When the first display member constituting member 21 is a protective panel, the print layer 3 is generally formed in a frame shape on the post-curing pressure-sensitive adhesive layer 11 ′ side of the first display member constituting member 21. is there.

  The material which comprises the printing layer 3 is not specifically limited, The well-known material for printing is used. The thickness of the printing layer 3, that is, the height of the step, is usually about 3 to 50 μm. The post-curing pressure-sensitive adhesive layer 11 ′ can exhibit sufficient followability with respect to such a printed layer 3, and no bubbles or the like can be generated at the interface with the printed layer 3.

  Examples of the display body 2 include a liquid crystal (LCD) display, a light emitting diode (LED) display, an organic electroluminescence (organic EL) display, electronic paper, and the like, and may be a touch panel. Moreover, as the display body 2, the member which comprises those some may be sufficient.

  In order to manufacture the said display body 2, as an example, one peeling sheet 12a of the adhesive sheet 1 is peeled, and the adhesive layer 11 which the adhesive sheet 1 exposed is used as the printing layer of the 1st display body structural member 21. It is bonded to the surface on the side where 3 is present. At this time, since the pressure-sensitive adhesive layer 11 is excellent in the initial step followability, it is possible to suppress the occurrence of gaps and floats in the vicinity of the step due to the printing layer 3.

  Next, the other release sheet 12b is peeled from the pressure-sensitive adhesive layer 11 of the pressure-sensitive adhesive sheet 1, and the pressure-sensitive adhesive layer 11 exposed from the pressure-sensitive adhesive sheet 1 and the second display member constituting member 22 are bonded together to obtain a laminate. . As another example, the bonding order of the first display member constituting member 21 and the second display member constituting member 22 may be switched.

  After obtaining the said laminated body, an active energy ray is irradiated with respect to the adhesive layer 11 in the said laminated body. Irradiation of the active energy ray to the pressure-sensitive adhesive layer 11 is usually performed through one of the first display member constituting member 21 and the second display member constituting member 22, and preferably the first display as a protective panel. Performed through the body component 21. At this time, you may irradiate an active energy ray through the display body structural member (1st display body structural member 21) which consists of a plastic plate containing an ultraviolet absorber. As described above, the active energy ray having a wavelength for curing the pressure-sensitive adhesive layer 11 is difficult to be absorbed by the ultraviolet absorber, and therefore, the pressure-sensitive adhesive layer 11 is sufficiently cured by the irradiation of the active energy ray and is thus cured. It becomes layer 11 '. Thereby, the display body 2 excellent in blister resistance is obtained.

As described above, the active energy ray used in the present embodiment has substantial intensity of light emission in a wavelength region exceeding the wavelength of 365 nm. Preferable examples of the active energy ray irradiation light source include a high-pressure mercury lamp, a metal halide lamp, and a xenon lamp. As for the irradiation amount of the said active energy ray, it is preferable that illumination intensity is about 50-1000 mW / cm < ² >. Further, the light quantity is preferably 50~10000mJ / cm ^2, more preferably 80~5000mJ / cm ^2, and particularly preferably 200~2000mJ / cm ^2.

In the display body 2 according to the present embodiment, the water vapor permeability of the first display body constituting member 21 is 0.001 g / (m ² · 24 h) or more and 100 g / (m ² · 24 h) or less. The water vapor permeability of the display member constituting member 22 is preferably 0.001 g / (m ² · 24 h) or less. Here, when a plastic plate is used as the first display member constituting member 21 and a glass plate is used as the second display member constituting member 22, the first display member constituting member 21 and the second display member constituting member are used. The water vapor permeability of 22 easily falls within the above range. When the display body 2 including the first display body constituent member 21 and the second display body constituent member 22 is placed under a high-temperature and high-humidity condition, external moisture, in particular, the first display body constituent member 21 It penetrates and penetrates and easily reaches the pressure-sensitive adhesive layer 11 ′ after curing. However, since the post-curing pressure-sensitive adhesive layer 11 ′ is derived from the pressure-sensitive adhesive sheet 1 according to the present embodiment, the generation of blisters and the whitening of the post-curing pressure-sensitive adhesive layer 11 ′ can be satisfactorily suppressed. Water vapor permeability as described above in the first display-constituting member 21, it is possible in particular 0.05g ^/ (m 2 · 24h) or more preferably, more 0.1g ^/ (m 2 · 24h) or higher Is preferred. The water vapor permeability is particularly preferably 80 g / (m ² · 24 h) or less, and more preferably 50 g / (m ² · 24 h) or less. The water vapor permeability described above in the second display member constituting member 22 is particularly preferably 0.0001 g / (m ² · 24 h) or more, and more preferably 0.0005 g / (m ² · 24 h) or more. Is preferred.

  The water vapor permeability of each of the first display member constituting member 21 and the second display member constituting member 22 described above is a transmittance measuring device in accordance with JIS K7129 under the conditions of 40 ° C. and 90% RH. It is measured using. In this measurement, the thicknesses of the first display member constituting member 21 and the second display member constituting member 22 are the same as those actually used for the display member 2. Therefore, the water vapor transmission rate described above is not the water vapor transmission rate as the material of each of the first display body constituting member 21 and the second display body constituting member 22, but the water vapor transmission rate as a member constituting the display body 2. It is a representation.

  In the display body 2 according to the present embodiment, the post-curing pressure-sensitive adhesive layer 11 ′ is obtained from the pressure-sensitive adhesive layer 11 (adhesive composition P) described above, and therefore the display body 2 is subjected to severe high-temperature and high-humidity conditions. Even when placed at (for example, 85 ° C., 85% RH, 1000 hours), the generation of blisters at the interface between the display member constituting members 21, 22 and the post-curing adhesive layer 11 ′ is suppressed. Further, even when the display body 2 is placed under severe high temperature and high humidity conditions (for example, 85 ° C., 85% RH, 1000 hours) and then returned to normal temperature and humidity, the post-curing pressure-sensitive adhesive layer 11 ′ is whitened. Is suppressed.

  In addition, this invention also provides the structure which comprises a part of display body (display body 2) mentioned above. The structure includes one display body constituent member, another display body constituent member, and a post-curing pressure-sensitive adhesive layer that bonds the one display body constituent member and the other display body constituent member together. Is done. The one display member constituting member is an ultraviolet shielding member having ultraviolet shielding properties. The other display member constituting member may be an ultraviolet ray transmissive member having ultraviolet ray permeability.

  The post-curing pressure-sensitive adhesive layer is obtained by curing an active energy ray-curable pressure-sensitive adhesive layer. This active energy ray-curable pressure-sensitive adhesive layer is preferably the pressure-sensitive adhesive layer 11 of the pressure-sensitive adhesive sheet 1 according to the above embodiment, and the display member constituting member that is an ultraviolet shielding member with respect to the pressure-sensitive adhesive layer 11. It is preferable that the active energy ray is irradiated through the adhesive layer 11 to make the adhesive layer 11 into a fully cured adhesive layer after curing.

  As the one display member constituting member, for example, a protective panel including a plastic plate containing an ultraviolet absorber is preferably exemplified. Moreover, as said other display body structural member, a glass plate, various optical members mentioned above, etc. are mentioned, for example.

  The embodiment described above is described for facilitating understanding of the present invention, and is not described for limiting the present invention. Therefore, each element disclosed in the above embodiment is intended to include all design changes and equivalents belonging to the technical scope of the present invention.

  For example, one of the release sheets 12a and 12b in the pressure-sensitive adhesive sheet 1 may be omitted. Further, the first display member constituting member 21 may have a step other than the printing layer 3 or may not have a step. Further, not only the first display member constituting member 21 but also the second display member constituting member 22 may have a step on the cured adhesive layer 11 ′ side.

  EXAMPLES Hereinafter, although an Example etc. demonstrate this invention further more concretely, the scope of the present invention is not limited to these Examples etc.

[Example 1]
1. Preparation of (meth) acrylic acid ester polymer (A) Solution weight of 55 parts by mass of 2-ethylhexyl acrylate, 5 parts by mass of N-acryloylmorpholine, 15 parts by mass of isobornyl acrylate, and 25 parts by mass of 2-hydroxyethyl acrylate The (meth) acrylic acid ester polymer (A) was prepared by copolymerization using a legal method. When the molecular weight of this (meth) acrylic acid ester polymer (A) was measured by the method described later, it was a weight average molecular weight (Mw) of 600,000. Further, the glass transition temperature (Tg; ° C.) of the (meth) acrylic acid ester polymer (A) is used as the glass transition temperature (homopolymer of each monomer constituting the (meth) acrylic acid ester polymer (A) ( It was -36.5 degreeC when computed by the formula of FOX based on Tg).

2. Preparation of Adhesive Composition 100 parts by mass (converted to solid content; the same applies hereinafter) of the (meth) acrylic acid ester polymer (A) obtained in Step 1 above, and trimethylolpropane-modified tris as a crosslinking agent (B) 0.18 parts by mass of diisocyanate (manufactured by Toyochem, product name “BHS8515”) and ε-caprolactone-modified tris- (2-acryloxyethyl) isocyanurate (Shin-Nakamura Chemical Co., Ltd.) as the active energy ray-curable component (C) 7 parts by mass, product name “A-9300-1CL”), 0.7 part by mass of 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide (D1) as a photopolymerization initiator (D), 3-glycidoxypropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., product name “KBM-403”) 0.2 as a silane coupling agent Mixing a mass parts, sufficiently stirred, by dilution with methyl ethyl ketone to obtain a coating solution of the adhesive composition.

Here, Table 1 shows each formulation (solid content converted value) of the adhesive composition when the (meth) acrylic acid ester polymer (A) is 100 parts by mass (solid content converted value). Details of the abbreviations and the like described in Table 1 are as follows.
[(Meth) acrylic acid ester polymer (A)]
2EHA: 2-ethylhexyl acrylate BA: n-butyl acrylate ACMO: N-acryloylmorpholine IBXA: isobornyl acrylate HEA: 2-hydroxyethyl acrylate HEMA: 2-hydroxyethyl methacrylate
[Photopolymerization initiator (D)]
D1: 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide D2: bis (2,4-cyclopentadienyl) bis [2,6-difluoro-3- (1-pyryl) phenyl] titanium (IV)
D3: Mixture in which benzophenone and 1-hydroxycyclohexyl phenyl ketone are mixed at a mass ratio of 1: 1

3. Manufacture of an adhesive sheet The coating solution of the adhesive composition obtained by the said process 2 is the heavy peeling type release sheet (product name "SP-PET752150 by the Lintec company) which peeled one side of the polyethylene terephthalate film with the silicone type release agent. The coating layer (thickness: 50 μm) was formed by applying heat treatment at 90 ° C. for 1 minute on the release treatment surface of “)”. A light release release sheet (product name “SP-PET381130, manufactured by Lintec Corporation) in which the surface on the application layer side of the obtained heavy release release sheet with an application layer and one surface of a polyethylene terephthalate film were subjected to a release treatment with a silicone release agent. )) And then cured under conditions of 23 ° C. and 50% RH for 7 days, a heavy release type release sheet / active energy ray-curable adhesive layer (thickness: 50 μm) / A pressure-sensitive adhesive sheet composed of a light release type release sheet was prepared.

  In addition, the thickness of the said adhesive layer is the value measured using the constant pressure thickness measuring device (The product name "PG-02" by the Teclock company) based on JISK7130.

[Examples 2 to 4]
Types and proportions of monomers constituting the (meth) acrylate polymer (A), weight average molecular weight (Mw) of the (meth) acrylate polymer (A), and types and blends of the crosslinking agent (B) A pressure-sensitive adhesive sheet was produced in the same manner as in Example 1 except that the amount was changed as shown in Table 1.

Example 5
1. Preparation of (meth) acrylic acid ester polymer (A) 50 parts by mass of 2-ethylhexyl acrylate, 5 parts by mass of N-acryloylmorpholine, 15 parts by mass of isobornyl acrylate, and 30 parts by mass of 2-hydroxyethyl acrylate The (meth) acrylic acid ester polymer (A) was prepared by copolymerization using a legal method. When the molecular weight of this (meth) acrylic acid ester polymer (A) was measured by the method described later, it was a weight average molecular weight (Mw) of 600,000. Further, the glass transition temperature (Tg; ° C.) of the (meth) acrylic acid ester polymer (A) is used as the glass transition temperature (homopolymer of each monomer constituting the (meth) acrylic acid ester polymer (A) ( It was -33.6 degreeC when computed by the formula of FOX based on Tg).

2. Preparation of adhesive composition 100 parts by mass of the (meth) acrylic acid ester polymer (A) obtained in the above step 1 and trimethylolpropane-modified tolylene diisocyanate (product name, manufactured by Toyochem Co., Ltd.) as a crosslinking agent (B) “BHS8515”) 0.20 part by mass and ε-caprolactone-modified tris- (2-acryloxyethyl) isocyanurate (made by Shin-Nakamura Chemical Co., Ltd., product name “A-9300” as the active energy ray-curable component (C) -1CL ") 7 parts by mass, 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide (D1) 0.7 part by mass as a photopolymerization initiator (D), and 3-particulate as a silane coupling agent Glycidoxypropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., product name “KBM-403”) 0.28 parts by mass is mixed sufficiently And 拌, by dilution with methyl ethyl ketone to obtain a coating solution of the adhesive composition.

3. Manufacture of an adhesive sheet The coating solution of the adhesive composition obtained by the said process 2 is the heavy peeling type release sheet (product name "SP-PET752150 by the Lintec company) which peeled one side of the polyethylene terephthalate film with the silicone type release agent. )) Was applied to the release-treated surface with a knife coater, and then heat-treated at 90 ° C. for 1 minute to form an application layer (thickness: 50 μm), thereby producing a heavy release release sheet with an application layer. .

  On the other hand, a light release type release sheet (product name “SP-PET381130”, manufactured by Lintec Co., Ltd.), in which one side of a polyethylene terephthalate film was release-treated with a silicone-based release agent, from the adhesive composition obtained in the above step After coating with a knife coater on the release treated surface of the film, heat treatment was performed at 90 ° C. for 1 minute to form a coating layer (thickness: 50 μm), thereby preparing four lightly peelable release sheets with a coating layer. .

  The surface on the coating layer side in the heavy release type release sheet with the coating layer obtained as described above, and the surface on the coating layer side in one of the light release type release sheet with the coating layer obtained as described above, Was applied to obtain a first laminate in which a coating layer having a total thickness of 100 μm was sandwiched between a heavy release release sheet and a light release release sheet.

  Subsequently, the exposed surface of the coating layer exposed by peeling the light release type release sheet from the first laminate, in one of the light release type release sheets with the coating layer obtained above. The surface on the coating layer side was affixed to obtain a second laminate in which the coating layer having a total thickness of 150 μm was sandwiched between the heavy release release sheet and the light release release sheet.

  Subsequently, the exposed surface of the coating layer exposed by peeling the light release type release sheet from the second laminate, in one of the light release type release sheets with the coating layer obtained above. The surface on the coating layer side was affixed to obtain a third laminate in which the coating layer having a total thickness of 200 μm was sandwiched between the heavy release release sheet and the light release release sheet.

  Furthermore, with respect to the exposed surface of the coating layer exposed by peeling the light release type release sheet from the third laminate, the remaining one of the light release type release sheets with the application layer obtained as described above The surface on the side of the coating layer was affixed to obtain a fourth laminate in which the coating layer having a total thickness of 250 μm was sandwiched between the heavy release release sheet and the light release release sheet.

  The fourth laminate is cured for 7 days under the conditions of 23 ° C. and 50% RH, so that a heavy release type release sheet / active energy ray-curable pressure-sensitive adhesive layer (thickness: 250 μm) / light release type A pressure-sensitive adhesive sheet composed of a release sheet was prepared.

Example 6
A pressure-sensitive adhesive sheet was produced in the same manner as in Example 5 except that the type of the photopolymerization initiator (D) was changed as shown in Table 1.

[Examples 7 to 8, Comparative Examples 1 to 6]
Kind and ratio of each monomer constituting (meth) acrylate polymer (A), weight average molecular weight (Mw) of (meth) acrylate polymer (A), blending amount of crosslinking agent (B), activity A pressure-sensitive adhesive sheet was produced in the same manner as in Example 1 except that the amount of the energy ray-curable component (C) and the type and amount of the photopolymerization initiator (D) were changed as shown in Table 1.

Here, the above-mentioned weight average molecular weight (Mw) is a polystyrene-reduced weight average molecular weight measured under the following conditions (GPC measurement) using gel permeation chromatography (GPC).
<Measurement conditions>
GPC measurement device: manufactured by Tosoh Corporation, HLC-8020
GPC column (passed in the following order): TSK guard column HXL-H manufactured by Tosoh Corporation
TSK gel GMHXL (× 2)
TSK gel G2000HXL
・ Measurement solvent: Tetrahydrofuran ・ Measurement temperature: 40 ° C.

[Test Example 1] (Measurement of water vapor permeability)
The coating solution of the adhesive composition prepared in Examples and Comparative Examples was prepared from a heavy release type release sheet (product name “SP-PET752150” manufactured by Lintec Corporation) in which one side of a polyethylene terephthalate film was released with a silicone release agent. After applying the release treatment surface with a knife coater, heat treatment was performed at 90 ° C. for 1 minute to form an application layer (thickness: 50 μm), thereby preparing a heavy release type release sheet with an application layer.

  On the other hand, a light release type release sheet (product name “SP-PET381130”, manufactured by Lintec Co., Ltd.) in which the coating solution of the adhesive composition prepared in Examples and Comparative Examples was subjected to release treatment on one side of a polyethylene terephthalate film with a silicone release agent. ) Was applied to the release-treated surface with a knife coater, and then heat-treated at 90 ° C. for 1 minute to form an application layer (thickness: 50 μm), thereby preparing a light release type release sheet with an application layer.

  The surface on the coating layer side in the heavy release type release sheet with the coating layer obtained as described above and the surface on the coating layer side in the light release type release sheet with the coating layer obtained as described above are pasted and thickened. A laminate was obtained in which a coating layer having a total thickness of 100 μm was sandwiched between a heavy release release sheet and a light release release sheet. By curing the laminate for 7 days under conditions of 23 ° C. and 50% RH, a heavy release type release sheet, an active energy ray-curable pressure-sensitive adhesive layer having a thickness of 100 μm, a light release type release sheet, Produced a pressure-sensitive adhesive sheet laminated in this order.

The light release type release sheet was peeled off from the obtained adhesive sheet, and a 2.0 mm thick plastic plate F (polymethyl methacrylate resin (PMMA) layer laminated on a polycarbonate resin (PC) plate on the exposed adhesive layer F ( The surface of the polycarbonate resin (PC) plate side of the UV absorber was bonded. Next, the active energy ray-curable pressure-sensitive adhesive layer was irradiated with active energy rays through the plastic plate F under the following conditions to cure the pressure-sensitive adhesive layer to obtain a pressure-sensitive adhesive layer after curing.
<Active energy ray irradiation conditions>
・ Use high pressure mercury lamp ・ Illuminance 200mW / cm ² , Light quantity 1000mJ / cm ²
-Uses "UVPF-A1" manufactured by Eye Graphics as the illuminance / light meter.

Subsequently, the pressure-sensitive adhesive layer after curing is sandwiched between two Tetron meshes # 380, and a transmittance measuring machine (product name “L80-5000”, manufactured by LYSSY) in accordance with JIS K7129 under the conditions of 40 ° C. and 90% RH. )), Water vapor permeability (g / (m ² · 24h · 100 µm)) was measured. The results are shown in Table 2.

[Test Example 2] (Measurement of absorbance)
An acetonitrile solution having a concentration of 0.1% by mass of the photopolymerization initiator used in Examples and Comparative Examples was prepared, and the absorbance in the wavelength range of 200 to 500 nm was measured using UV-Vis-NIR (UV-Vis-NIR). ) Measurement was performed using a spectrophotometer (manufactured by Shimadzu Corporation, product name “UV-3600”). Based on the result, an absorbance at a wavelength of 390 nm and an absorption maximum wavelength (nm) at an absorbance at a wavelength of 200 to 500 nm were derived. The results are shown in Table 1.

[Test Example 3] (Measurement of gel fraction)
The pressure-sensitive adhesive sheets obtained in Examples and Comparative Examples were cut into a size of 80 mm × 80 mm, the active energy ray-curable pressure-sensitive adhesive layer was wrapped in a polyester mesh (mesh size 200), and the mass was measured on a precision balance. Weighed and subtracted the mass of the mesh alone to calculate the mass of the adhesive alone. The mass at this time is M1.

  Next, the pressure-sensitive adhesive wrapped in the polyester mesh was immersed in ethyl acetate at room temperature (23 ° C.) for 24 hours. Thereafter, the pressure-sensitive adhesive was taken out, air-dried for 24 hours in an environment of a temperature of 23 ° C. and a relative humidity of 50%, and further dried in an oven at 80 ° C. for 12 hours. After drying, the mass was weighed with a precision balance, and the mass of the pressure sensitive adhesive alone was calculated by subtracting the mass of the mesh alone. The mass at this time is M2. The gel fraction (%) is represented by (M2 / M1) × 100. This derived | led-out the gel fraction (before active energy ray irradiation) of an adhesive (active energy ray hardening adhesive). The results are shown in Table 2.

  The light release type release sheet was peeled off from the obtained adhesive sheet, and a 2.0 mm thick plastic plate F (polymethyl methacrylate resin (PMMA) layer laminated on a polycarbonate resin (PC) plate on the exposed adhesive layer F ( The surface of the polycarbonate resin (PC) plate side of the UV absorber was bonded. Next, the active energy ray-curable pressure-sensitive adhesive layer is irradiated with active energy rays through the plastic plate F under the same active energy ray irradiation conditions as in Test Example 1, and the pressure-sensitive adhesive layer is cured and cured. It was set as the adhesive layer. About the adhesive of this adhesive layer after hardening, the gel fraction (after active energy ray irradiation) was derived | led-out similarly to the above. Moreover, the value (change amount; point) which deducted the gel fraction before active energy ray irradiation from the gel fraction after active energy ray irradiation was computed. The results are shown in Table 2.

[Test Example 4] (Measurement of adhesive strength)
The light release type release sheet was peeled from the pressure sensitive adhesive sheets obtained in Examples and Comparative Examples, and the exposed pressure sensitive adhesive layer was replaced with a polyethylene terephthalate (PET) film having an easy-adhesive layer (product name “PET A4300” manufactured by Toyobo Co., Ltd.). , Thickness: 100 μm) to obtain a laminate of heavy release type release sheet / active energy ray curable pressure sensitive adhesive layer / PET film. The obtained laminate was cut into a width of 25 mm and a length of 100 mm.

  In an environment of 23 ° C. and 50% RH, the heavy release type release sheet is peeled from the laminate, and the exposed adhesive layer is attached to soda lime glass (manufactured by Nippon Sheet Glass Co., Ltd.). And pressurized at 0.5 MPa and 50 ° C. for 20 minutes. Thereafter, a plastic plate F (containing an ultraviolet absorber) having a thickness of 2.0 mm in which a polymethyl methacrylate resin (PMMA) layer was laminated on a polycarbonate resin (PC) plate was placed on the PET film. Then, through the plastic plate F and the PET film, the adhesive layer is irradiated with active energy rays under the same active energy ray irradiation conditions as in Test Example 1, and the active energy ray-curable adhesive layer is cured and cured. It was set as the back adhesive layer. After leaving for 24 hours under conditions of 23 ° C. and 50% RH, a sample having the post-curing pressure-sensitive adhesive layer was used with a tensile tester (Orientec Co., Tensilon), peeling speed of 300 mm / min, peeling angle. The adhesive strength (N / 25 mm) was measured under the condition of 180 degrees. Conditions other than those described here were measured according to JIS Z 0237: 2009. The results are shown in Table 2.

[Test Example 5] (Measurement of haze value)
The light release type release sheet was peeled off from the obtained adhesive sheet, and a 2.0 mm thick plastic plate F (polymethyl methacrylate resin (PMMA) layer laminated on a polycarbonate resin (PC) plate on the exposed adhesive layer F ( The surface of the polycarbonate resin (PC) plate side of the UV absorber was bonded. Next, the active energy ray-curable pressure-sensitive adhesive layer is irradiated with active energy rays through the plastic plate F under the same active energy ray irradiation conditions as in Test Example 1, and the pressure-sensitive adhesive layer is cured and cured. It was set as the adhesive layer. About this adhesive layer after hardening, haze value (%) was measured using the haze meter (Nippon Denshoku Industries Co., Ltd. product name "NDH-2000") according to JISK7136: 2000. The results are shown in Table 2.

[Test Example 6] (Measurement of step following rate)
On the surface of a glass plate (manufactured by NSG Precision, product name “Corning Glass Eagle XG”, length 90 mm × width 50 mm × thickness 0.5 mm), UV curable ink (product name “POS-911 Black”, manufactured by Teikoku Ink Co., Ltd.) ) Was screen-printed in a frame shape (outer shape: 90 mm long × 50 mm wide, 5 mm wide) so that the coating thickness was any one of 10 μm, 15 μm, 20 μm and 30 μm. Next, irradiation with ultraviolet rays (80 W / cm ² , ^two metal halide lamps, lamp height of 15 cm, belt speed of 10 to 15 m / min) is performed to cure the printed ultraviolet curable ink, and a level difference due to printing (level difference) A stepped glass plate having a thickness of any one of 10 μm, 15 μm, 20 μm, 30 μm, 50 μm, 100 μm and 150 μm) was produced.

  The light release type release sheet was peeled off from the pressure sensitive adhesive sheets obtained in Examples and Comparative Examples, and the exposed active energy ray-curable pressure sensitive adhesive layer was replaced with a polyethylene terephthalate (PET) film (product made by Toyobo Co., Ltd., product) It was bonded to an easy-adhesion layer having the name “PET A4300” (thickness: 100 μm). Next, the heavy release type release sheet is peeled off to expose the pressure-sensitive adhesive layer, and each step is provided so that the pressure-sensitive adhesive layer covers the entire frame-like printed surface using a laminator (product name “LPD3214” manufactured by Fuji Plastics). Laminated on a glass plate. Then, it was autoclaved for 30 minutes under the conditions of 50 ° C. and 0.5 MPa, and left at normal pressure, 23 ° C. and 50% RH for 24 hours.

Next, a plastic plate F (containing an ultraviolet absorber) having a thickness of 2.0 mm in which a polymethyl methacrylate resin (PMMA) layer was laminated on a polycarbonate resin (PC) plate was placed on the PET film. Then, through the plastic plate F and the PET film, the active energy ray-curable adhesive layer is irradiated with active energy rays under the same active energy ray irradiation conditions as in Test Example 1 to cure the adhesive layer. After curing, a pressure-sensitive adhesive layer was obtained. Subsequently, the laminate was stored for 72 hours under a high-temperature and high-humidity condition of 85 ° C. and 85% RH (endurance test), and then the step following ability was evaluated. Step followability is determined by whether or not the printed step is completely filled with the post-curing adhesive layer, and bubbles, floats, peeling, etc. are observed at the interface between the printed step and the post-curing adhesive layer. It is determined that the printing step cannot be followed. Here, the step following property was evaluated as a step following rate (%) represented by the following formula. The results are shown in Table 2.
Step follow-up rate (%) = {(height of the step where the embedded state is maintained without bubbles, floats, peeling, etc. after the durability test) / (thickness of the adhesive layer after curing)} × 100

[Test Example 7] (Evaluation of blister resistance)
The active energy ray-curable pressure-sensitive adhesive layers of the pressure-sensitive adhesive sheets obtained in Examples and Comparative Examples were prepared using soda lime glass (manufactured by Nippon Sheet Glass Co., Ltd., thickness: 1.1 mm) and a plastic plate (UV cut property) shown in Table 2. (None / UV cut). Then, it was autoclaved for 20 minutes under the conditions of 50 ° C. and 0.5 MPa, and left for 24 hours at normal pressure, 23 ° C. and 50% RH. The plastic plates shown in Table 2 are as follows.
[No UV cut]
・ Plastic plate A: Acrylic resin plate (thickness: 0.7 mm, no UV absorber)
・ Plastic plate B: A plastic plate (thickness: 1.5 mm, UV absorber-free) with a polymethyl methacrylate resin (PMMA) layer laminated on a polycarbonate resin (PC) plate, the polycarbonate resin (PC) plate side is adhesive Contact with the layer ・ Plastic plate C: Polycarbonate resin plate (thickness: 2 mm, no UV absorber)
[With UV cut property]
・ Plastic plate D: Plastic plate (thickness: 0.7 mm, containing UV absorber) with a polymethyl methacrylate resin (PMMA) layer laminated on a polycarbonate resin (PC) plate, and the adhesive layer on the polycarbonate resin (PC) plate side・ Plastic plate E: A plastic plate (thickness: 1 mm, containing UV absorber) with a polymethyl methacrylate resin (PMMA) layer laminated on a polycarbonate resin (PC) plate, the adhesive layer on the polycarbonate resin (PC) plate side・ Plastic plate F: A plastic plate (thickness: 2 mm, containing UV absorber) with a polymethyl methacrylate resin (PMMA) layer laminated on a polycarbonate resin (PC) plate, the adhesive layer on the polycarbonate resin (PC) plate side Contact

Next, the active energy ray-curable adhesive layer is irradiated with active energy rays through the plastic plate under the same active energy ray irradiation conditions as in Test Example 1 to cure the adhesive layer after curing. It was set as the adhesive layer. Subsequently, the laminate was stored for 1000 hours under high temperature and high humidity conditions of 85 ° C. and 85% RH. Thereafter, the state at the interface between the adhesive layer after curing and the adherend was visually confirmed, and blister resistance was evaluated according to the following criteria. The results are shown in Table 2.
◎… There were no air bubbles, no floating or peeling.
A: Two or one bubbles having a diameter of less than 1 mm were generated, but there was no floating / peeling.
Δ: 3 or more and 9 or less bubbles having a diameter of less than 1 mm were generated, but there was no floating or peeling.
X: Bubbles, floating and peeling occurred.

[Test Example 8] (Evaluation of resistance to moist heat whitening)
The active energy ray-curable pressure-sensitive adhesive layers of the pressure-sensitive adhesive sheets obtained in Examples and Comparative Examples were prepared by using a non-alkali glass plate having a thickness of 1.1 mm and a polymethyl methacrylate resin (PMMA) on a polycarbonate resin (PC) plate. The laminate (Configuration A) was obtained by sandwiching the layer between the 0.7 mm-thick plastic plate D (containing an ultraviolet absorber) and the polycarbonate resin (PC) plate side. The obtained laminate was autoclaved for 20 minutes at 50 ° C. and 0.5 MPa, and then allowed to stand at normal pressure, 23 ° C. and 50% RH for 24 hours.

  Thereafter, the active energy ray-curable pressure-sensitive adhesive layer is irradiated with active energy rays through the plastic plate under the same active energy ray irradiation conditions as in Test Example 1, and the pressure-sensitive adhesive layer is cured and cured. It was set as the agent layer.

  About the laminated body after active energy ray irradiation, the haze value (%) was measured according to JISK7136: 2000 using the haze meter (Nippon Denshoku Industries Co., Ltd. make, product name "NDH2000"). The results are shown in Table 2 as the haze value (%) before the durability test according to Configuration A.

  Next, the laminated body after irradiation with active energy rays is stored for 1000 hours under a wet heat condition of 85 ° C. and 85% RH (endurance test), and then for 24 hours at 23 ° C. and 50% RH at normal temperature and humidity. I left it alone. About the said laminated body, haze value (%) was measured similarly to the above. The results are shown in Table 2 as the haze value (%) after the durability test according to Configuration A.

  Based on the above results, the difference was calculated by subtracting the haze value (%) before the durability test from the haze value (%) after the durability test. The results are shown in Table 2 as the difference (points) in haze values before and after the durability test according to Configuration A.

Furthermore, based on the difference (point) in the haze value before and after the calculated durability test, the wet heat whitening resistance was evaluated according to the following criteria. The results are shown in Table 2 as moisture heat whitening resistance according to Configuration A.
A: The difference in haze values is less than 1.5 points.
A: The difference in haze value is 1.5 points or more and less than 8.0 points.
X: The difference in haze value is 8.0 points or more.

  In addition, it can be said that the post-curing pressure-sensitive adhesive layer in which the evaluation of the resistance to moist and heat whitening is “◎” shows no whitening at all and can be used favorably for a display body or the like. Although it can be said that the post-curing pressure-sensitive adhesive layer that has become “◯” is observed to be white, it can also be used for a display body or the like. The post-curing pressure-sensitive adhesive layer that was “x” was observed to be whitened and can be said to be unsuitable for use in a display body or the like.

  Furthermore, in the laminate according to the above configuration A, a plastic plate D (containing an ultraviolet absorber) having a thickness of 0.7 mm obtained by laminating a polymethyl methacrylate resin (PMMA) layer on a polycarbonate resin (PC) plate is added to a polycarbonate resin ( A laminate (Configuration B) was prepared by changing to a plastic plate F (containing an ultraviolet absorber) having a thickness of 2.0 mm in which a polymethyl methacrylate resin (PMMA) layer was laminated on a PC) plate. For the laminate according to Configuration B, as in the laminate according to Configuration A, the haze value (%) before the durability test and the haze value (%) after the durability test are measured, and the haze value before and after the durability test is measured. The difference (point) was calculated, and the resistance to moist heat whitening was evaluated. These results are shown in Table 2.

[Test Example 9] (Measurement of light transmittance)
Using the haze meter (product name “NDH5000” manufactured by Nippon Denshoku Industries Co., Ltd.), the light transmittance (%) of the ultraviolet absorbent-containing plastic plate used in Test Examples 7 and 8 (with UV cut property) It measured based on JISK7361-1: 1997. Table 3 shows the measurement results of the light transmittance at a wavelength of 360 nm and the light transmittance at a wavelength of 390 nm.

  As can be seen from Table 2, the post-curing pressure-sensitive adhesive layer formed by using the pressure-sensitive adhesive sheets obtained in the examples is resistant to blister resistance and heat-and-whitening resistance even when subjected to severe high temperature and high humidity conditions. It was excellent.

  The pressure-sensitive adhesive sheet of the present invention can be suitably used, for example, for bonding a protective panel made of a plastic plate containing an ultraviolet absorber and a display member constituting member in a display body of a car navigation system.

DESCRIPTION OF SYMBOLS 1 ... Adhesive sheet 11 ... Adhesive layer 12a, 12b ... Release sheet 2 ... Display body 11 '... Adhesive layer after hardening 21 ... 1st display body structural member 22 ... 2nd display body structural member 3 ... Printing layer

Claims (10)

A pressure-sensitive adhesive sheet comprising a pressure-sensitive adhesive layer for laminating one display member constituting member and another display member constituting member,
At least one of the one display member constituting member and the other display member constituting member is made of a plastic plate,
The pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer is
(Meth) acrylic acid ester polymer (A) containing 10% by mass or more and 50% by mass or less of a monomer having a hydroxyl group in the molecule as a monomer constituting the polymer;
A crosslinking agent (B);
An active energy ray-curable component (C);
It is obtained from an adhesive composition containing a photopolymerization initiator (D) having an absorbance at a wavelength of 390 nm in an acetonitrile solution having a concentration of 0.1% by mass, and the (meth) acrylic acid ester polymer ( A) contains a cross-linked structure obtained by cross-linking each other via the cross-linking agent (B), the unreacted active energy ray-curable component (C), and the photopolymerization initiator (D). An adhesive sheet, which is an active energy ray-curable adhesive.   The pressure-sensitive adhesive sheet according to claim 1, wherein the plastic plate contains an ultraviolet absorber.   The pressure-sensitive adhesive sheet according to claim 1 or 2, wherein the active energy ray-curable pressure-sensitive adhesive has a gel fraction of 30% to 70%. Two release sheets,
The pressure-sensitive adhesive sheet according to any one of claims 1 to 3, further comprising the pressure-sensitive adhesive layer sandwiched between the release sheets so as to be in contact with the release surfaces of the two release sheets. A display member constituting member;
Other display body components,
A display body comprising a post-curing pressure-sensitive adhesive layer that bonds the one display body constituent member and the other display body constituent member together,
At least one of the one display member constituting member and the other display member constituting member is made of a plastic plate,
The display body, wherein the post-curing pressure-sensitive adhesive layer is a post-curing pressure-sensitive adhesive layer obtained by curing the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet according to any one of claims 1 to 4 with active energy rays. .   The display body according to claim 5, wherein a gel fraction of the post-curing pressure-sensitive adhesive layer is 40% or more and 95% or less. The plastic plate has a water vapor permeability of 0.001 g / (m ² · 24 h · 100 μm) or more and 100 g / (m ² · m ² ) measured according to JIS K7129 under the conditions of 40 ° C. and 90% RH with a thickness of 100 μm. The display body according to claim 5 or 6, wherein the display body is made of a material having a thickness of 24h · 100µm or less. The water vapor permeability of the one display member constituting member measured according to JIS K7129 under the conditions of 40 ° C. and 90% RH is 0.001 g / (m ² · 24 h) or more and 100 g / (m ² · 24 h). And
The water vapor permeability measured in accordance with JIS K7129 under the conditions of 40 ° C. and 90% RH of the other display member constituting member is 0.001 g / (m ² · 24 h) or less. The display body as described in any one of 5-7. The laminated body formed by bonding one display body structural member and another display body structural member through the adhesive layer of the adhesive sheet according to any one of claims 1 to 4,
The manufacturing method of the display body characterized by irradiating an active energy ray with respect to the said adhesive layer of the said laminated body, hardening the said adhesive layer, and setting it as the adhesive layer after hardening.   The method of manufacturing a display body according to claim 9, wherein the active energy ray is irradiated to the pressure-sensitive adhesive layer through a display body constituent member made of a plastic plate containing an ultraviolet absorber.

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