JP6558287B2 - Image display device laminate and image display device manufacturing method - Google Patents

Description

  The present invention relates to an image display device such as a personal computer, a mobile terminal (PDA), a game machine, a television (TV), a car navigation system, a touch panel, a pen tablet, etc., and an image display for configuring such an image display device. The present invention relates to a method for manufacturing a laminated body for device configuration.

  In recent years, in order to improve the visibility of an image display device, an image display panel such as a liquid crystal display (LCD), a plasma display (PDP), an electroluminescence display (ELD), and a protection disposed on the front side (viewing side). By filling the gap between the panel and the touch panel member with an adhesive, reflection of incident light and outgoing light from the display image at the air layer interface is suppressed.

  As a method for filling the gap between the constituent members for an image display device with an adhesive, there is a method in which a liquid adhesive resin composition containing an ultraviolet curable resin is filled into the gap and then cured by irradiation with ultraviolet rays. Known (Patent Document 1).

  In addition, a method of filling a gap between constituent members for an image display device using an adhesive sheet is also known. For example, Patent Document 2 discloses a method in which a pressure-sensitive adhesive sheet that has undergone primary crosslinking with ultraviolet rays is bonded to an image display device constituent member, and then the adhesive sheet is irradiated with ultraviolet rays through the image display device constituent member to be secondarily cured. .

  Patent Document 3 discloses a pressure-sensitive adhesive sheet comprising a hot-melt adhesive composition having a loss tangent at 25 ° C. of less than 1 based on urethane (meth) acrylate having a weight average molecular weight of 20,000 to 100,000. And a method for filling a gap between constituent members for an image display device.

International Publication No. 2010/027041 Japanese Patent No. 4971529 International Publication No. 2010/038366

By the way, when sticking two image display apparatus structural members using the adhesive sheet which consists of an adhesive resin composition containing a base resin, a crosslinking agent, and an ultraviolet polymerization initiator, two image display apparatus structural members are attached. After first sticking through the pressure-sensitive adhesive sheet, UV light is irradiated from the outside of one image display device constituent member, and the pressure-sensitive adhesive sheet is UV-cured through the image display device constituent member and secondarily attached. According to this, the primary adhesion can be performed while filling the unevenness of the adherend surface, and the adhesion reliability can be further enhanced by finally curing with ultraviolet rays.
However, among the image display device constituent members, there are members that are easily deteriorated by ultraviolet rays. In such a case, the two image display device constituent members cannot be attached by the method described above. Further, in the case where the image display device component has ultraviolet absorptivity, the ultraviolet ray does not reach the adhesive sheet sufficiently even if the ultraviolet ray is irradiated through the member. Therefore, there is a problem that the two image display device constituent members cannot be attached.

  On the other hand, as the image display device is thinner, a new function is required for the adhesive sheet. In order to prevent UV deterioration of liquid crystals, organic EL elements, polarizing plates, etc., image display device constituent members may be required to have an ultraviolet absorbing function, and the ultraviolet absorbing function is generally secured by a polarizing plate protective film. It was. However, along with the thinning of the constituent members of the image display device, the polarizing plate protective film is also thinned, and it has become difficult to obtain a sufficient ultraviolet absorption function. Therefore, an ultraviolet ray absorbing function is also required for image display device constituent members other than the polarizing plate protective film, such as an adhesive and an adhesive sheet.

  However, it is difficult to impart an ultraviolet absorbing function to the ultraviolet curable adhesive sheet as described above. On the other hand, when the adhesive surface is used to fill the unevenness of the adherend surface and primary adhesion is applied and then the method of further curing and secondary attachment is not adopted, the attachment surface of the bonding member has unevenness There was a problem that it was not possible to achieve both the level difference absorbability and the anti-foaming reliability after bonding.

  Therefore, the present invention can provide a new image display that can be further cured and secondarily adhered after the two image display device constituent members are primarily adhered using an adhesive sheet, and which does not need to be irradiated with ultraviolet rays. It is intended to provide a method for manufacturing a laminated body for device configuration.

The present invention is a method of manufacturing a laminate for constituting an image display device having a constitution in which image display device constituting members are laminated via a double-sided pressure-sensitive adhesive sheet, and includes at least the following steps (1) to (3): The manufacturing method of the laminated body for image display apparatus structures which has this is proposed.
(1) Double-sided adhesive from an adhesive composition containing a (meth) acrylic copolymer (A), a crosslinking agent (B), and a photopolymerization initiator (C) having an absorption coefficient of 10 or more at a wavelength of 405 nm. A step of producing a sheet.
(2) The process of laminating | stacking two image display apparatus structural members through the double-sided adhesive sheet before photocuring.
(3) After laminating two image display device constituting members through the double-sided adhesive sheet, the light containing at least a wavelength of 405 nm is included through the image display device constituting member from the outside of at least one image display device constituting member. And a step of irradiating the double-sided pressure-sensitive adhesive sheet with light substantially free of light having a wavelength of 380 nm or less to cause the double-sided pressure-sensitive adhesive sheet to be crosslinked by visible light and curing.

  According to the method for manufacturing a laminate for constituting an image display device proposed by the present invention, after first sticking using an adhesive sheet, it can be further photocured and secondarily stuck. It is possible to achieve both the level difference absorbability when there is unevenness on the wearing surface and the anti-foaming reliability after bonding. In addition, since the ultraviolet ray is not irradiated, the image display device constituent member can be adhered even to an image display device constituent member that is easily deteriorated by ultraviolet rays or an image display device constituent member having ultraviolet absorptivity.

  Hereinafter, an example of an embodiment of the present invention will be described in detail. However, the present invention is not limited to the following embodiment.

<This laminated body manufacturing method>
A method for producing a laminate for constituting an image display device according to an example of an embodiment of the present invention (referred to as “the present laminate production method”) includes a (meth) acrylic copolymer (A), a cross-linking as necessary. After the pressure-sensitive adhesive composition (referred to as “the present pressure-sensitive adhesive composition”) containing the agent (B) and the photopolymerization initiator (C) is formed into a sheet (“sheet preparation step”), the present pressure-sensitive adhesive composition Two image display device constituent members are laminated via a double-sided pressure-sensitive adhesive sheet (this adhesive sheet) before photocuring (“primary sticking step”), and then outside of at least one image display device constituent member Through the image display device constituting member, the adhesive sheet is irradiated with light containing at least light having a wavelength of 405 nm and substantially free of light having a wavelength of 380 nm or less to cure the adhesive sheet by visible light crosslinking. ("Secondary sticking process") A manufacturing method characterized by making an image display device configured for laminate.

<Sheet preparation process>
In this step, the pressure-sensitive adhesive composition is formed into a sheet shape to produce the pressure-sensitive adhesive sheet. However, this step may be introduced as necessary.

As a method for forming the present pressure-sensitive adhesive resin composition into a sheet, a currently known method can be arbitrarily employed.
At this time, the pressure-sensitive adhesive resin composition may be formed into a sheet on the release film to produce the pressure-sensitive adhesive sheet.
Alternatively, the pressure-sensitive adhesive resin composition may be formed into a sheet on an image display device constituent member and the pressure-sensitive adhesive sheet may be laminated on the image display device constituent member.

<Primary sticking process>
If this pressure-sensitive adhesive sheet has self-adhesiveness (tackiness) as will be described later, it is possible to perform primary adhesion simply by overlapping two image display device constituent members via this pressure-sensitive adhesive sheet.

  For example, if this pressure-sensitive adhesive sheet is based on a (meth) acrylic copolymer (A1) composed of a graft copolymer having a macromonomer as a branch component, as described later, at room temperature. In addition to being able to exhibit self-adhesion while maintaining the sheet shape, in an uncrosslinked state, in a normal state, that is, near room temperature, an appropriate adhesiveness, for example, an adhesive property that can be peeled off (referred to as “tackiness”) ), It is possible to facilitate positioning and the like when sticking. Furthermore, since it can be melted or flowed when heated in an uncrosslinked state (hot melt property), the pressure-sensitive adhesive can be filled following uneven portions such as printing steps, and filling is performed without generating bubbles. be able to.

  A well-known apparatus can be used for the bonding apparatus used when laminating. For example, an electrothermal press machine provided with a heating plate, a diaphragm type laminator, a roll laminator, a vacuum bonding machine, a hand roll, and the like can be given.

When the (meth) acrylic copolymer (A1) comprising a graft copolymer having a macromonomer as a branch component is used as a base polymer, the present adhesive sheet is excellent in a normal state, that is, a room temperature state. Storage stability and cutting processability can be imparted. Moreover, since it has self-adhesiveness (tackiness), it is possible to obtain adhesiveness to the extent that it can be easily attached by simply pressing the adhesive sheet against the adherend, so positioning for adhering adhesive material can be achieved. It is easy to do and very convenient for work. Furthermore, since it is also excellent in shape retention, it can be processed into an arbitrary shape in advance, so that the present adhesive sheet formed on the release film is used for laminating the image display device constituent member. It can also be cut in advance according to the dimensions.
The cutting method at this time is generally punched with a Thomson blade, cut with a super cutter or laser, and half-cuts leaving either the front or back release film in a frame shape so that the release film can be easily peeled off. Is more preferable.

In addition, if the pressure-sensitive adhesive sheet has hot-melt properties, that is, a property of being softened or fluidized by heating, even if the adherend surface has irregularities, the adhesive sheet can be heated to follow the irregularities. Thus, even the unevenness can be filled without gaps.
At this time, as a heating means of the pressure-sensitive adhesive sheet, for example, various thermostats, a hot plate, an electromagnetic heating device, a heating roll, or the like can be used. In order to perform bonding and heating more efficiently, for example, an electrothermal press, a diaphragm type laminator, a roll laminator, or the like is preferably used. At this time, for example, one or both of the image display device constituent members can be heated to heat the pressure-sensitive adhesive sheet.

Moreover, if the softening temperature of this adhesive sheet is 50 degreeC or more, a process characteristic and the storage characteristic in normal temperature can be made enough. On the other hand, if the softening temperature of the pressure-sensitive adhesive sheet is 100 ° C. or less, not only can the thermal damage to the image display panel or the front panel be suppressed, but also the pressure-sensitive adhesive sheet can be prevented from flowing too much. it can.
Therefore, the softening temperature of the present pressure-sensitive adhesive sheet is preferably 50 to 100 ° C., more preferably 55 ° C. or more and 95 ° C. or less, and particularly preferably 60 ° C. or more and 90 ° C. or less.

Moreover, after laminating | stacking and laminating | stacking two image display apparatus structural members through this adhesive sheet, a laminated body can be heated in a pressure-reduced environment.
By heating the laminate in a reduced pressure environment, it is possible to prevent air bubbles from being mixed into the pressure-sensitive adhesive sheet after adhering or foreign matters from being mixed therein.

<Secondary sticking process>
In the secondary sticking step, the image display device constituting member is formed from the outside of at least one image display device constituting member with respect to a laminate formed by laminating two image display device constituting members via the adhesive sheet. Through which the pressure-sensitive adhesive sheet is irradiated with light that contains at least light with a wavelength of 405 nm and does not substantially contain light with a wavelength of 380 nm or less, preferably visible light that does not substantially contain light with a wavelength of 380 nm or less. Is photocrosslinked and cured.

  Since this pressure-sensitive adhesive sheet can be firmly cross-linked by photocrosslinking in this way, for example, an adhesive force that can sufficiently counteract the gas pressure of outgas generated from image display device constituent members such as a protective panel. It can have cohesive strength.

Here, “substantially free of light having a wavelength of 380 nm or less” means that the emission intensity of light having a wavelength of 380 nm or less is 5 mW / cm ² or less, preferably 1 mW / cm ² or less.

  As a method of irradiating visible light that does not include light having a wavelength of 380 nm or less, that is, light having a wavelength in the ultraviolet region, a light source that emits only visible light that does not include light having a wavelength in the ultraviolet region may be used. For example, a light source composed of at least one kind selected from the sun, a fluorescent lamp, an LED, an organic EL, an inorganic EL, and a light emitting module for an image display device, or a combination of two or more kinds can be used.

Moreover, you may make it irradiate through the filter which does not permeate | transmit the light of the wavelength of an ultraviolet region. For example, when a light source such as a high pressure mercury lamp, a metal halide lamp, a xenon arc lamp, or a carbon arc lamp that emits light having a wavelength in the ultraviolet region or sunlight is used as a light source, the light transmittance at a wavelength of 380 nm is less than 10%. In addition, a method of irradiating the adhesive composition with visible light through a filter having a light transmittance of 60% or more at a wavelength of 405 nm can be mentioned.
The filter may be a release film constituting the pressure-sensitive adhesive sheet laminate or a surface protective film used by being laminated on the surface of the pressure-sensitive adhesive sheet laminate.

  In order to adjust the degree of visible light crosslinking, in addition to the method of controlling the amount of visible light irradiation, the visible light is partially blocked by irradiating visible light through the filter. It is also possible to adjust the degree of crosslinking.

<This adhesive sheet>
This pressure-sensitive adhesive sheet is a pressure-sensitive adhesive containing a (meth) acrylic copolymer (A), a crosslinking agent (B), a photopolymerization initiator (C), and, if necessary, an ultraviolet absorber (D). It is a transparent double-sided pressure-sensitive adhesive sheet made of the composition.

[(Meth) acrylic copolymer (A)]
The (meth) acrylic copolymer as the base polymer of the pressure-sensitive adhesive sheet has a glass transition temperature (Tg) depending on the type, composition ratio, polymerization conditions, and the like of the acrylic monomer and methacrylic monomer used to polymerize the copolymer. These characteristics can be adjusted as appropriate.

  The “base polymer” in the pressure-sensitive adhesive sheet means a resin that forms the main component of the pressure-sensitive adhesive sheet. The specific content is not specified. As a guide, it is a resin that occupies 50% by mass or more of the resin contained in the pressure-sensitive adhesive sheet, especially 65% by mass or more, of which 80% by mass (including 100% by mass) or more. In addition, when two or more types of base polymers are used, the total amount thereof corresponds to the content.

  Examples of the (meth) acrylic copolymer (A) include a copolymer obtained by polymerizing a homopolymer of alkyl (meth) acrylate and a monomer component having copolymerizability with the homopolymer of alkyl (meth) acrylate. More preferably, the alkyl (meth) acrylate is selected from a carboxyl group-containing monomer, a hydroxyl group-containing monomer, an amino group-containing monomer, an epoxy group-containing monomer, an amide group-containing monomer and other vinyl monomers copolymerizable therewith. And a copolymer containing any one or more monomers as monomer components.

  More specifically, a linear or branched alkyl (meth) acrylate having 4 to 18 carbon atoms in the side chain (hereinafter also referred to as “copolymerizable monomer A”), a carboxyl group-containing monomer (hereinafter referred to as “copolymerizable monomer A”). (Also referred to as “copolymerizable monomer B”), vinyl monomer (hereinafter also referred to as “copolymerizable monomer C”), (meth) acrylate having 1 to 3 carbon atoms in the side chain (hereinafter referred to as “copolymerizable monomer D”). And a copolymer composed of any one or more monomers selected from a hydroxyl group-containing monomer (hereinafter “copolymerizable monomer E”).

  Further, (a) a copolymer composed of a monomer component including a copolymerizable monomer A and a copolymerizable monomer B and / or a copolymerizable monomer C; and (b) a copolymerizable monomer A and a copolymer. A copolymer composed of a monomer component containing a polymerizable monomer B and / or a copolymerizable monomer C and a copolymerizable monomer D and / or a copolymerizable monomer E can also be mentioned as a particularly preferred example. Specifically, a copolymer of copolymerizable monomers A and B, a copolymer of copolymerizable monomers A and C, a copolymer of copolymerizable monomers A, B and C, a copolymerizable monomer A, B And D copolymer, copolymerizable monomer A, B and E copolymer, copolymerizable monomer A, B, D and E copolymer, copolymerizable monomer A, C and D copolymer , Copolymers of copolymerizable monomers A, C and E, copolymers of copolymerizable monomers A, C, D and E, copolymers of copolymerizable monomers A, B, C and D, copolymerizable Mention may be made of copolymers of monomers A, B, C and E and copolymers of copolymerizable monomers A, B, C, D and E.

  Examples of the “copolymerizable monomer A” include n-butyl (meth) acrylate, isobutyl (meth) acrylate, sec-butyl (meth) acrylate, t-butyl (meth) acrylate, pentyl (meth) acrylate, and isopentyl. (Meth) acrylate, neopentyl (meth) acrylate, hexyl (meth) acrylate, cyclohexyl (meth) acrylate, heptyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, isooctyl (meth) acrylate , Nonyl (meth) acrylate, isononyl (meth) acrylate, t-butylcyclohexyl (meth) acrylate, decyl (meth) acrylate, isodecyl (meth) acrylate, undecyl (meth) acrylate , Lauryl (meth) acrylate, tridecyl (meth) acrylate, tetradecyl (meth) acrylate, cetyl (meth) acrylate, stearyl (meth) acrylate, isostearyl (meth) acrylate, isobornyl (meth) acrylate, 3, 5, Examples include 5-trimethylcyclohexane (meth) acrylate, dicyclopentanyl (meth) acrylate, dicyclopentenyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, and the like. These may be used alone or in combination of two or more.

  The copolymerizable monomer A is preferably contained in an amount of 30% by mass or more and 90% by mass or less, and particularly 35% by mass or 88% by mass, particularly 40% by mass or more. Or it is more preferable to contain in 85 mass% or less.

  Examples of the “copolymerizable monomer B” include (meth) acrylic acid, 2- (meth) acryloyloxyethyl hexahydrophthalic acid, 2- (meth) acryloyloxypropylhexahydrophthalic acid, 2- (meth). Acryloyloxyethylphthalic acid, 2- (meth) acryloyloxypropylphthalic acid, 2- (meth) acryloyloxyethylmaleic acid, 2- (meth) acryloyloxypropylmaleic acid, 2- (meth) acryloyloxyethylsuccinic acid, Examples include 2- (meth) acryloyloxypropyl succinic acid, crotonic acid, fumaric acid, maleic acid, and itaconic acid. These may be used alone or in combination of two or more. “(Meth) acryl” means to include acrylic and methacrylic. Similarly, “(meth) acryloyl” means acryloyl and methacryloyl.

  Examples of the “copolymerizable monomer C” include compounds having a vinyl group in the molecule. Examples of such compounds include (meth) acrylic acid alkyl esters having 1 to 12 carbon atoms in the alkyl group, and functional monomers having a functional group such as a hydroxyl group, an amide group, and an alkoxyl alkyl group in the molecule; Polyalkylene glycol di (meth) acrylates and vinyl ester monomers such as vinyl acetate, vinyl propionate and vinyl laurate, and aromatic vinyl monomers such as styrene, chlorostyrene, chloromethylstyrene, α-methylstyrene and other substituted styrenes Can be illustrated. These may be used alone or in combination of two or more.

  The copolymerizable monomer B and the copolymerizable monomer C are 1.2% by mass to 15% by mass or less in the total monomer components of the copolymer, and particularly 1.5% by mass or more from the viewpoint of obtaining excellent adhesive properties. Alternatively, it is preferably contained in an amount of 10% by mass or less, and more preferably 2% by mass or more or 8% by mass or less.

  Examples of the “copolymerizable monomer D” include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, i-propyl (meth) acrylate and the like. These may be used alone or in combination of two or more.

  The copolymerizable monomer D is preferably contained in the total monomer component of the copolymer in an amount of 0% by mass or more and 70% by mass or less, particularly 3% by mass or more or 65% by mass or less, and more preferably 5% by mass or more. More preferably, it is contained in the range of 60% by mass or less.

  Examples of the “copolymerizable monomer E” include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate and the like. Mention may be made of (meth) acrylates. These may be used alone or in combination of two or more.

  The copolymerizable monomer E is preferably contained in an amount of 0% by mass or more and 30% by mass or less in all monomer components of the copolymer, particularly 0% by mass or more or 25% by mass or less. More preferably, it is contained in the range of 20% by mass or less.

  In addition to the above, acid anhydride group-containing monomers such as maleic anhydride and itaconic anhydride, glycidyl (meth) acrylate, glycidyl α-ethyl acrylate, epoxy such as 3,4-epoxybutyl (meth) acrylate Group-containing monomer, amino group-containing (meth) acrylic acid ester monomer such as dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, (meth) acrylamide, Nt-butyl (meth) acrylamide, N-methylol Monomers containing amide groups such as (meth) acrylamide, N-methoxymethyl (meth) acrylamide, N-butoxymethyl (meth) acrylamide, diacetone (meth) acrylamide, maleic acid amide, maleimide, vinyl pyrrolidone, vinyl pyridine, Vinylca Heterocyclic basic monomers such as Bazoru can be used as needed.

  Specific examples of the (meth) acrylic copolymer include, for example, 2-ethylhexyl (meth) acrylate, octyl (meth) acrylate, decyl (meth) acrylate, lauryl (meth) acrylate, and isostearyl (meth) acrylate. , Monomer component (a) such as butyl (meth) acrylate, ethyl (meth) acrylate, methyl (meth) acrylate, and (meth) acrylic acid having a carboxyl group, 2- (meth) acryloyloxyethyl hexahydrophthalic acid, 2- (meth) acryloyloxypropylhexahydrophthalic acid, 2- (meth) acryloyloxyethylphthalic acid, 2- (meth) acryloyloxypropylphthalic acid, 2- (meth) acryloyloxyethylmaleic acid, 2- (meth ) Acrylyloxypropylma A monomer component (b) such as inacid, 2- (meth) acryloyloxyethyl succinic acid, 2- (meth) acryloyloxypropyl succinic acid, crotonic acid, fumaric acid, maleic acid, itaconic acid, and organic functional groups. Hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, glycerol (meth) acrylate, monomethyl maleate, monomethyl itaconate, vinyl acetate, glycidyl (meth) acrylate, (meth) acrylamide, Mention may be made of (meth) acrylic acid ester copolymers obtained by copolymerizing monomer components (c) such as (meth) acrylonitrile, fluorinated (meth) acrylates and silicone (meth) acrylates.

  The weight average molecular weight of the (meth) acrylic copolymer is preferably 100,000 to 1,500,000, more preferably 150,000 or more and 1.3 million or less, and particularly preferably 200,000 or more or 1,200,000 or less.

  In order to obtain an adhesive composition having a high cohesive force, the mass average molecular weight is 700,000 to 1,500,000, particularly 800,000 to 1,300,000 or less from the viewpoint of obtaining cohesive force by entanglement of molecular chains as the molecular weight increases. Is preferred. On the other hand, when it is desired to obtain an adhesive composition having high fluidity and stress relaxation properties, the mass average molecular weight is preferably 70,000 to 700,000, particularly 100,000 or more or 600,000 or less. In addition, when a solvent is not used when forming an adhesive sheet or the like, it is difficult to use a polymer having a large molecular weight, so the mass average molecular weight of the acrylic copolymer is 70,000 to 700,000, particularly 100,000 or more. Alternatively, it is preferably 600,000 or less, particularly preferably 150,000 or more or 500,000 or less.

((Meth) acrylic copolymer (A1))
As an example of a preferable base polymer of the pressure-sensitive adhesive sheet, a (meth) acrylic copolymer (A1) composed of a graft copolymer including a macromonomer as a branch component can be exemplified.

If this adhesive sheet is comprised using the said (meth) acrylic-type copolymer (A1) as a base resin, this adhesive sheet can show self-adhesiveness, hold | maintaining a sheet form in a room temperature state, An uncrosslinked state It has a hot melt property that melts or flows when heated in, and can be photocured, and after photocuring, it can exhibit excellent cohesive force for adhesion.
Therefore, if the (meth) acrylic copolymer (A1) is used as the base polymer of the pressure-sensitive adhesive sheet, it exhibits adhesiveness at room temperature (20 ° C.) even in an uncrosslinked state, and is 50 to 90 ° C. More preferably, it can have a property of softening or fluidizing when heated to a temperature of 60 ° C. or higher or 80 ° C. or lower, that is, a hot melt property.

The glass transition temperature of the copolymer constituting the trunk component of the (meth) acrylic copolymer (A1) is preferably −70 to 0 ° C.
In this case, the glass transition temperature of the copolymer component constituting the trunk component is the glass transition of the polymer obtained by copolymerizing only the monomer component constituting the trunk component of the (meth) acrylic copolymer (A1). Refers to temperature. Specifically, it means a value calculated by the Fox formula from the glass transition temperature and the composition ratio of the polymer obtained from the homopolymer of each component of the copolymer.
In addition, the calculation formula of Fox is a calculation value calculated | required by the following formula | equation, Polymer handbook [Polymer HandBook, J.M. Brandrup, Interscience, 1989].
1 / (273 + Tg) = Σ (Wi / (273 + Tgi))
[Wherein Wi represents the weight fraction of monomer i, and Tgi represents Tg (° C.) of the homopolymer of monomer i. ]

The glass transition temperature of the copolymer component constituting the trunk component of the (meth) acrylic copolymer (A1) is the flexibility of the pressure-sensitive adhesive sheet at room temperature and the wetness of the pressure-sensitive adhesive sheet to the adherend. The glass transition temperature is preferably −70 ° C. to 0 ° C. in order for the pressure-sensitive adhesive sheet to obtain appropriate adhesiveness (tackiness) at room temperature. It is particularly preferably −65 ° C. or higher or −5 ° C. or lower, and particularly preferably −60 ° C. or higher or −10 ° C. or lower.
However, even if the glass transition temperature of the copolymer component is the same temperature, the viscoelasticity can be adjusted by adjusting the molecular weight. For example, it can be made more flexible by reducing the molecular weight of the copolymer component.

Examples of the (meth) acrylic acid ester monomer contained in the trunk component of the (meth) acrylic copolymer (A1) include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) ) Acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, sec-butyl (meth) acrylate, t-butyl (meth) acrylate, pentyl (meth) acrylate, isopentyl (meth) acrylate, neopentyl (meth) acrylate , Hexyl (meth) acrylate, cyclohexyl (meth) acrylate, heptyl (meth) acrylate, 2-ethylhexyl acrylate, n-octyl acrylate, isooctyl acrylate, nonyl (meth) acrylate, isononi (Meth) acrylate, t-butylcyclohexyl (meth) acrylate, decyl (meth) acrylate, isodecyl (meth) acrylate, undecyl (meth) acrylate, lauryl (meth) acrylate, cetyl (meth) acrylate, stearyl (meth) acrylate, Isostearyl (meth) acrylate, behenyl (meth) acrylate, isobornyl (meth) acrylate, 2-phenoxyethyl (meth) acrylate, 3,5,5-trimethylcyclohexane acrylate, p-cumylphenol EO modified (meth) acrylate, Examples include dicyclopentanyl (meth) acrylate, dicyclopentenyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, and benzyl (meth) acrylate. Can. These include hydroxyl-containing (meth) acrylates such as hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, and glycerol (meth) acrylate having a hydrophilic group or an organic functional group, ) Acrylic acid, 2- (meth) acryloyloxyethylhexahydrophthalic acid, 2- (meth) acryloyloxypropylhexahydrophthalic acid, 2- (meth) acryloyloxyethylphthalic acid, 2- (meth) acryloyloxypropylphthalate Acid, 2- (meth) acryloyloxyethylmaleic acid, 2- (meth) acryloyloxypropylmaleic acid, 2- (meth) acryloyloxyethylsuccinic acid, 2- (meth) acryloyloxypropylsuccinic acid, crotonic acid, fumaric acid Carboxyl group-containing monomers such as maleic acid, itaconic acid, monomethyl maleate and monomethyl itaconic acid, acid anhydride group-containing monomers such as maleic anhydride and itaconic anhydride, glycidyl (meth) acrylate, glycidyl α-ethyl acrylate , Epoxy group-containing monomers such as (meth) acrylic acid 3,4-epoxybutyl, amino group-containing (meth) acrylic acid ester monomers such as dimethylaminoethyl (meth) acrylate and diethylaminoethyl (meth) acrylate, (meth) Acrylamide, Nt-butyl (meth) acrylamide, N-methylol (meth) acrylamide, N-methoxymethyl (meth) acrylamide, N-butoxymethyl (meth) acrylamide, diacetone acrylamide, maleic acid amide, maleimide, etc. Monomers containing amide group, vinyl pyrrolidone, vinyl pyridine, can also be used heterocyclic basic monomers such as vinyl carbazole.
In addition, styrene, t-butylstyrene, α-methylstyrene, vinyltoluene, acrylonitrile, methacrylonitrile, vinyl acetate, vinyl propionate, alkyl vinyl ether, hydroxyalkyl vinyl ether, alkyl, which can be copolymerized with the above acrylic monomers and methacrylic monomers. Various vinyl monomers such as vinyl monomers can also be used as appropriate.

Further, the trunk component of the (meth) acrylic copolymer (A1) preferably contains a hydrophobic (meth) acrylate monomer and a hydrophilic (meth) acrylate monomer as constituent units.
When the trunk component of the (meth) acrylic copolymer (A1) is composed only of a hydrophobic monomer, a tendency to wet-heat whitening is observed, and thus hydrophilic monomers are also introduced into the trunk component to prevent wet-heat whitening. Is preferred.

  Specifically, as the main component of the (meth) acrylic copolymer (A1), a hydrophobic (meth) acrylate monomer, a hydrophilic (meth) acrylate monomer, and a polymerizable functional group at the end of the macromonomer. A copolymer component formed by random copolymerization with a group can be exemplified.

Here, examples of the hydrophobic (meth) acrylate monomer include n-butyl (meth) acrylate, isobutyl (meth) acrylate, sec-butyl (meth) acrylate, t-butyl (meth) acrylate, and pentyl (meth) ) Acrylate, isopentyl (meth) acrylate, neopentyl (meth) acrylate, hexyl (meth) acrylate, cyclohexyl (meth) acrylate, heptyl (meth) acrylate, 2-ethylhexyl acrylate, n-octyl acrylate, isooctyl acrylate, nonyl (meta) ) Acrylate, isononyl (meth) acrylate, t-butylcyclohexyl (meth) acrylate, decyl (meth) acrylate, isodecyl (meth) acrylate, undecyl (meth) acrylate , Lauryl (meth) acrylate, cetyl (meth) acrylate, stearyl (meth) acrylate, isostearyl (meth) acrylate, behenyl (meth) acrylate, isobornyl (meth) acrylate, cyclohexyl (meth) acrylate, dicyclopentenyloxyethyl Examples thereof include (meth) acrylate and methyl methacrylate.
Examples of the hydrophobic vinyl monomer include vinyl acetate, styrene, t-butyl styrene, α-methyl styrene, vinyl toluene, and alkyl vinyl monomers.

  Examples of the hydrophilic (meth) acrylate monomer include methyl acrylate, (meth) acrylic acid, tetrahydrofurfuryl (meth) acrylate, hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) ) Acrylate, hydroxyl-containing (meth) acrylate such as glycerol (meth) acrylate, (meth) acrylic acid, 2- (meth) acryloyloxyethylhexahydrophthalic acid, 2- (meth) acryloyloxypropylhexahydrophthalic acid, 2- (meth) acryloyloxyethyl phthalic acid, 2- (meth) acryloyloxypropyl phthalic acid, 2- (meth) acryloyloxyethyl maleic acid, 2- (meth) acryloyloxypropyl maleic acid, 2- ( TA) carboxyl group-containing monomers such as acryloyloxyethyl succinic acid, 2- (meth) acryloyloxypropyl succinic acid, crotonic acid, fumaric acid, maleic acid, itaconic acid, monomethyl maleate, monomethyl itaconate, maleic anhydride, anhydrous Acid anhydride group-containing monomer such as itaconic acid, epoxy group-containing monomer such as glycidyl (meth) acrylate, glycidyl α-ethyl acrylate, 3,4-epoxybutyl (meth) acrylate, methoxypolyethylene glycol (meth) acrylate Examples thereof include alkoxy polyalkylene glycol (meth) acrylates such as N, N-dimethylacrylamide, hydroxyethylacrylamide and the like.

(Branch component: macromonomer)
The (meth) acrylic copolymer (A1) preferably contains a macromonomer-derived repeating unit by introducing a macromonomer as a branch component of the graft copolymer.
The macromonomer is a polymer monomer having a terminal polymerizable functional group and a high molecular weight skeleton component.

The glass transition temperature (Tg) of the macromonomer is preferably higher than the glass transition temperature of the copolymer component constituting the (meth) acrylic copolymer (A1).
Specifically, since the glass transition temperature (Tg) of the macromonomer affects the heating and melting temperature (hot melt temperature) of the present adhesive sheet, the glass transition temperature (Tg) of the macromonomer is 30 ° C to 120 ° C. Of these, 40 ° C. or higher or 110 ° C. or lower, and more preferably 50 ° C. or higher or 100 ° C. or lower among these.
With such a glass transition temperature (Tg), by adjusting the molecular weight, it is possible to maintain excellent processability and storage stability, and to adjust so as to hot-melt near 80 ° C.
The glass transition temperature of the macromonomer refers to the glass transition temperature of the macromonomer itself, and can be measured with a differential scanning calorimeter (DSC).

Further, at room temperature, the branch components are attracted to each other and can maintain a state where they are physically cross-linked as a pressure-sensitive adhesive composition, and the physical cross-linking is released by heating to an appropriate temperature. In order to obtain fluidity, it is also preferable to adjust the molecular weight and content of the macromonomer.
From this point of view, the macromonomer is preferably contained in the (meth) acrylic copolymer (A1) at a ratio of 5% by mass to 30% by mass, particularly 6% by mass or more, or 25% by mass or less. It is preferably 8% by mass or more or 20% by mass or less.
The number average molecular weight of the macromonomer is preferably 500 or more and less than 8000, more preferably 800 or more and less than 7500, and particularly preferably 1000 or more and less than 7000.
As the macromonomer, a generally produced one (for example, a macromonomer manufactured by Toa Gosei Co., Ltd.) can be appropriately used.

The high molecular weight skeleton component of the macromonomer is preferably composed of an acrylic polymer or a vinyl polymer.
Examples of the high molecular weight skeleton component of the macromonomer include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, and isobutyl (meth) acrylate. , Sec-butyl (meth) acrylate, t-butyl (meth) acrylate, pentyl (meth) acrylate, isopentyl (meth) acrylate, neopentyl (meth) acrylate, hexyl (meth) acrylate, cyclohexyl (meth) acrylate, heptyl (meth) ) Acrylate, 2-ethylhexyl acrylate, n-octyl acrylate, isooctyl acrylate, nonyl (meth) acrylate, isononyl (meth) acrylate, t-butylcyclohexyl ( (Meth) acrylate, decyl (meth) acrylate, isodecyl (meth) acrylate, undecyl (meth) acrylate, lauryl (meth) acrylate, cetyl (meth) acrylate, stearyl (meth) acrylate, isostearyl (meth) acrylate, behenyl (meth) ) Acrylate, isobornyl (meth) acrylate, 2-phenoxyethyl (meth) acrylate, 3,5,5-trimethylcyclohexane acrylate, p-cumylphenol EO modified (meth) acrylate, dicyclopentanyl (meth) acrylate, di Cyclopentenyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, benzyl (meth) acrylate, hydroxyalkyl (meth) acrylate, (meth) acrylic acid, (Meth) acrylate monomers such as lysidyl (meth) acrylate, (meth) acrylamide, N, N-dimethyl (meth) acrylamide, (meth) acrylonitrile, alkoxyalkyl (meth) acrylate, alkoxypolyalkylene glycol (meth) acrylate, , Styrene, t-butyl styrene, α-methyl styrene, vinyl toluene, alkyl vinyl monomer, vinyl acetate, alkyl vinyl ether, hydroxyalkyl vinyl ether, and other various vinyl monomers. These may be used alone or in combination of two or more. can do.

  Examples of the terminal polymerizable functional group of the macromonomer include a methacryloyl group, an acryloyl group, and a vinyl group.

[Crosslinking agent (B)]
The crosslinking agent (B) is, for example, selected from (meth) acryloyl group, epoxy group, isocyanate group, carboxyl group, hydroxyl group, carbodiimide group, oxazoline group, aziridine group, vinyl group, amino group, imino group, and amide group. The crosslinking agent which has at least 1 sort (s) of crosslinkable functional group can be mentioned, You may use 1 type or in combination of 2 or more types.
The crosslinkable functional group may be protected with a deprotectable protecting group.

  Examples of such polyfunctional (meth) acrylates include 1,4-butanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, glycerin di (meth) acrylate, glycerin glycidyl ether di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, 1,9-nonanediol di (meth) acrylate, tricyclodecane dimethanol di (meth) acrylate, bisphenol A polyethoxydi (meth) acrylate, bisphenol A polyalkoxydi (meth) ) Acrylate, bisphenol F polyalkoxy di (meth) acrylate, polyalkylene glycol di (meth) acrylate, trimethylolpropane trioxyethyl (meth) acrylate, ε-caprolactone modified (2-hydroxyethyl) isocyanurate tri (meth) acrylate, pentaerythritol tri (meth) acrylate, propoxylated pentaerythritol tri (meth) acrylate, ethoxylated pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate , Propoxylated pentaerythritol tetra (meth) acrylate, ethoxylated pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, polyethylene glycol di (meth) acrylate, tris (acryloxyethyl) isocyanurate, pentaerythritol tetra (Meth) acrylate, dipentaerythritol hexa (meth) acrylate, dipentaerythritol penta ) Acrylate, tripentaerythritol hexa (meth) acrylate, tripentaerythritol penta (meth) acrylate, hydroxybivalate neopentyl glycol di (meth) acrylate, hydroxybivalate neopent glycol ε-caprolactone adduct di ( In addition to UV-curable polyfunctional monomers such as (meth) acrylate, trimethylolpropane tri (meth) acrylate, alkoxylated trimethylolpropane tri (meth) acrylate, and ditrimethylolpropane tetra (meth) acrylate, polyester (meth) acrylate And polyfunctional acrylic oligomers such as epoxy (meth) acrylate, urethane (meth) acrylate, and polyether (meth) acrylate.

Among the above-mentioned polyfunctional (meth) acrylic acid ester monomers, polar functional groups such as a hydroxyl group, a carboxyl group, and an amide group from the viewpoint of improving the adhesion to the adherend and the effect of suppressing wet heat whitening. Polyfunctional monomers or oligomers containing are preferred. Among these, it is preferable to use a polyfunctional (meth) acrylic acid ester having a hydroxyl group or an amide group.
From the viewpoint of preventing moist heat whitening, the (meth) acrylic copolymer (A1), that is, the graft copolymer contains a hydrophobic acrylate monomer and a hydrophilic acrylate monomer as a trunk component. More preferably, a polyfunctional (meth) acrylic acid ester having a hydroxyl group is preferably used as the crosslinking agent (B).
Moreover, in order to adjust effects, such as adhesiveness, heat-and-moisture resistance, and heat resistance, you may further add monofunctional or polyfunctional (meth) acrylic acid ester which reacts with a crosslinking agent (B).

  Content of a crosslinking agent (B) is 0.1-20 with respect to 100 mass parts of said (meth) acrylic-type copolymers (A) from a viewpoint which balances the softness | flexibility and cohesion force which are adhesive composition. It is preferable to contain it by the ratio of a mass part, and it is especially preferable that it is a ratio of 0.5 mass part or more or 15 mass parts or less, and especially the ratio of 1 mass part or more or 13 mass parts or less.

[Photoinitiator (C)]
The photopolymerization initiator (C) used in the pressure-sensitive adhesive sheet serves as a reaction initiation assistant in the crosslinking reaction of the crosslinking agent (B), and is capable of visible light, for example, light in the wavelength region of 380 nm to 700 nm. Those that generate radicals by irradiation and serve as starting points for the polymerization reaction of the base resin are preferred. However, radicals may be generated only by irradiation with visible light, or radicals may be generated by irradiation with light in a wavelength region other than the visible light region.

  From this viewpoint, the photopolymerization initiator (C) has a molar extinction coefficient at a wavelength of 405 nm of 10 or more, particularly 15 or more, and particularly preferably 25 or more.

Examples of the photopolymerization initiator having a molar extinction coefficient of 10 or more at a wavelength of 405 nm include 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) butan-1-one, 2- (4-methylbenzyl) -2-dimethylamino-1- (4-morpholinophenyl) butan-1-one, bis (η ⁵ -2,4-cyclopentadien-1-yl) -bis (2,6-difluoro-3- (1H) -Pyrrol-1-yl) phenyl) titanium, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, (2,4,6-trimethylbenzoyl) ) Ethoxyphenylphosphine oxide, bis (2,6-dimethoxybenzoyl) 2,4,4-trimethylpentylphosphine oxide, thioxanthone, 2-c Lorothioxanthone, 3-methylthioxanthone, 2,4-dimethylthioxanthone, anthraquinone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone, 2-aminoanthraquinone, 1,2-octanedione, 1- (4 -(Phenylthio), 2- (o-benzoyloxime)), 1- [9-ethyl-6- (2-methylbenzoyl) -9H-carbazol-3-yl] -ethanone 1- (O-acetyloxime), In addition to camphorquinone, triazine photopolymerization initiators and the like can be mentioned.
Any one of these or derivatives thereof may be used, or two or more of these may be used in combination. Moreover, you may use together with the photoinitiator whose molar absorption coefficient of wavelength 405nm is less than 10.

Photopolymerization initiators are roughly classified into two types depending on the radical generation mechanism, a cleavage type photopolymerization initiator that can cleave and decompose a single bond of the photopolymerization initiator itself, and a photoexcited initiator. And a hydrogen donor in the system form an exciplex and can be roughly classified into a hydrogen abstraction type photopolymerization initiator that can transfer hydrogen of the hydrogen donor.
Among these, the cleavage type photopolymerization initiator is decomposed when a radical is generated by light irradiation to be another compound, and once excited, it does not function as a reaction initiator. For this reason, when the intramolecular cleavage type is used as the photopolymerization initiator (C) having an absorption wavelength in the visible light region, the photoreaction is carried out after the pressure-sensitive adhesive sheet is cross-linked by light irradiation as compared with the case of using the hydrogen abstraction type. The photopolymerizable initiator is preferable because it remains as an unreacted residue in the pressure-sensitive adhesive composition and is unlikely to cause an unexpected change with time or promotion of crosslinking. Further, the coloring specific to the photopolymerizable initiator is also preferable because it becomes a reaction decomposition product, so that absorption in the visible light region is eliminated and a color to be erased can be appropriately selected.
On the other hand, a hydrogen abstraction type photopolymerization initiator does not generate a decomposition product such as a cleavage type photopolymerization initiator during radical generation reaction by irradiation of active energy rays such as ultraviolet rays, so that it is difficult to become a volatile component after completion of the reaction. Damage to the body can be reduced.

  Examples of the cleavage type photopolymerization initiator include 2,2-dimethoxy-1,2-diphenylethane-1-one, 1-hydroxycyclohexyl phenyl ketone, and 2-hydroxy-2-methyl-1-phenyl-propane-1. -One, 1- (4- (2-hydroxyethoxy) phenyl) -2-hydroxy-2-methyl-1-propan-1-one, 2-hydroxy-1- [4- {4- (2-hydroxy- 2-methyl-propionyl) benzyl} phenyl] -2-methyl-propan-1-one, oligo (2-hydroxy-2-methyl-1- (4- (1-methylvinyl) phenyl) propanone), phenylglyoxy Methyl lickate, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) butan-1-one, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropane-1 -One, 2- (dimethylamino) -2 -[(4-Methylphenyl) methyl] -1- [4- (4-morpholinyl) phenyl] -1-butanone, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, 2,4,6 -Trimethylbenzoyldiphenylphosphine oxide, (2,4,6-trimethylbenzoyl) ethoxyphenylphosphine oxide, bis (2,6-dimethoxybenzoyl) 2,4,4-trimethylpentylphosphine oxide and their derivatives Can be mentioned.

Among these, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, 2,4,6-trimethylbenzoyldiphenylphosphine is a cleavage-type photopolymerization initiator, and becomes a degradation product after the reaction and discolors. Acylphosphine oxide photoinitiators such as fin oxide, (2,4,6-trimethylbenzoyl) ethoxyphenylphosphine oxide, bis (2,6-dimethoxybenzoyl) 2,4,4-trimethylpentylphosphine oxide are preferred.
Furthermore, from the compatibility with an acrylic copolymer comprising a graft copolymer having a macromonomer as a branch component, 2,4,6-trimethylbenzoyldiphenylphosphine oxide as a photopolymerization initiator (C), (2 , 4,6-Trimethylbenzoyl) ethoxyphenylphosphine oxide, bis (2,6-dimethoxybenzoyl) 2,4,4-trimethylpentylphosphine oxide, etc. are preferably used.

  The content of the photopolymerization initiator (C) is not particularly limited. For example, 0.1 to 10 parts by mass with respect to 100 parts by mass of the (meth) acrylic copolymer (A), in particular 0.2 to 5 parts by mass, among which 0.5 to 3 parts by mass It is particularly preferred to contain it in a proportion of not more than parts. However, this range may be exceeded in balance with other elements. A photoinitiator can be used 1 type or in combination of 2 or more types.

[Ultraviolet absorber (D)]
The ultraviolet absorber (D) may be any substance that can absorb ultraviolet rays. As a guideline, by adding the ultraviolet absorber (D), the absorbance at a wavelength of 380 nm of the double-sided pressure-sensitive adhesive sheet is 0.3 or more, especially 0.5. As mentioned above, it is preferable that it is a substance which can be made into 1 or more among them.

In addition, the light absorbency in wavelength 380nm is calculated | required from the following formula | equation.
_{A 380 = -Log (T 380/} 100)
A ₃₈₀ : Absorbance at a wavelength of 380 nm
T ₃₈₀ ; transmittance (%) at 380 nm of the double-sided PSA sheet

Examples of the ultraviolet absorber (D) include one or more structures selected from the group consisting of a benzotriazole structure, a benzophenone structure, a triazine structure, a benzoate structure, an oxalanilide structure, a salicylate structure, and a cyanoacrylate structure. What has is preferable.
Among these, those having one or two or more structures selected from the group consisting of a benzotriazole structure, a triazine structure and a benzophenone structure are preferable from the viewpoint of ultraviolet absorption.
Further, from the viewpoint of compatibility with an acrylic copolymer comprising a graft copolymer having a macromonomer as a branch component, it is preferable to use a benzotriazole structure or a benzophenone structure as the ultraviolet absorber (D).

  The content of the ultraviolet absorber (D) is not particularly limited. For example, with respect to 100 parts by weight of the (meth) acrylic copolymer (A), 0.01 to 10 parts by weight, especially 0.1 parts by weight or more or 5 parts by weight or less, among which 0.2 parts by weight or more or 3 parts by weight. It is particularly preferable to contain it in a proportion of not more than parts. However, this range may be exceeded in balance with other elements.

  From the viewpoint of starting photopolymerization in the visible light region excluding the ultraviolet rays while absorbing the ultraviolet rays, the ratio of the ultraviolet absorber (D) to 100 parts by mass of the photopolymerization initiator (C) is 25 to 400 parts by mass. However, it is particularly preferably 50 parts by mass or more and 300 parts by mass or less, and particularly preferably 80 parts by mass or more or 250 parts by mass or less. An ultraviolet absorber can be used 1 type or in combination of 2 or more types.

[Other ingredients]
This adhesive sheet may contain the well-known component mix | blended with the normal adhesive composition as components other than the above. For example, tackifying resins, silane coupling agents, antioxidants, light stabilizers, metal deactivators, rust inhibitors, anti-aging agents, hygroscopic agents, hydrolysis inhibitors, polymerization inhibitors, leveling agents, It is possible to appropriately contain various additives such as.
Moreover, you may contain a reaction catalyst (A tertiary amine type compound, a quaternary ammonium type compound, a lauric acid tin compound, etc.) suitably as needed.

[Preferred composition example]
As an example of a particularly preferred composition of the present pressure-sensitive adhesive composition, the (meth) acrylic copolymer (A) contains an acrylic copolymer composed of a graft copolymer having a macromonomer as a branch component, and is crosslinked. It contains a polyfunctional (meth) acrylic acid ester compound such as bifunctional and trifunctional as the agent (B), a cleavage type photopolymerization initiator as the photopolymerization initiator (C), and an ultraviolet absorber (D ), Examples of compositions containing an ultraviolet absorber having a benzotriazole structure or a benzophenone structure can be given. However, the composition is not limited to the above.

[Laminated structure]
The pressure-sensitive adhesive sheet may be a single-layer sheet or a multilayer sheet in which two or more layers are laminated.
When the pressure-sensitive adhesive sheet is a multilayer pressure-sensitive adhesive sheet, that is, when a pressure-sensitive adhesive sheet having a laminated structure including an intermediate layer and an outermost layer is formed, the outermost layer is formed from the pressure-sensitive adhesive composition. It is preferable.

When this pressure-sensitive adhesive sheet has a multilayer structure, the ratio of the thickness of each outermost layer and the thickness of the intermediate layer is preferably 1: 1 to 1:20, and more preferably 1: 2 to 1:10. Is more preferable.
If the thickness of the intermediate layer is within the above range, the contribution of the thickness of the pressure-sensitive adhesive layer in the laminate is not too large, and it is preferable that the workability relating to cutting and handling is not deteriorated because it is too flexible.
In addition, if the outermost layer is in the above range, it is preferable because the adhesion to the adherend and the wettability can be maintained without being inferior in conformity to unevenness and a bent surface.

[Sheet thickness]
With regard to the thickness of this adhesive sheet, it is possible to meet the demand for thinning by reducing the sheet thickness. On the other hand, if the sheet thickness is too thin, for example, if there is an uneven part on the adherend surface, it will follow the unevenness sufficiently. It may not be possible or it may not be able to exert sufficient adhesion.
From this viewpoint, the thickness of the pressure-sensitive adhesive sheet is preferably 20 to 500 μm, more preferably 25 μm or more and 350 μm or less, and particularly preferably 50 μm or more and 250 μm or less.

[Characteristics of this adhesive sheet]
The ultraviolet transmittance (JIS K7361-1) of the present pressure-sensitive adhesive sheet is preferably 50% or less at a wavelength of 380 nm, more preferably 30% or less, and most preferably 10% or less.

<Adhesive sheet laminate for image display device>
This pressure-sensitive adhesive sheet, that is, the pressure-sensitive adhesive sheet before the image display device constituting member is laminated, can be used alone as it is. Moreover, it is also possible to use it by laminating with other members.

  For example, a release film can be laminated on one side or both sides of the present adhesive sheet to form an adhesive sheet laminate for an image display device (referred to as “present adhesive sheet laminate”).

At this time, it is preferable that one or both release films have a light transmittance of 40% or less for light having a wavelength of 410 nm or less. If at least one release film has a light transmittance of 40% or less for light having a wavelength of 410 nm or less, the adhesive sheet has a molar extinction coefficient of 405 nm by laminating the release film on the present adhesive sheet. This is because even when the photopolymerization initiator (C) is 10 or more, it is possible to effectively prevent the photopolymerization from proceeding by irradiation with visible light.
From such a viewpoint, it is preferable that one or both of the release films have a light transmittance of 40% or less for light having a wavelength of 410 nm or less, more preferably 30% or less, and more preferably 20% or less.

  Here, as a release film having a light transmittance of 40% or less for light having a wavelength of 410 nm or less, that is, a release film having a function of partially blocking transmission of visible light and ultraviolet light, for example, an ultraviolet absorber is blended. Cast films and stretched films made of polyester, polypropylene, and polyethylene resins that have been subjected to release treatment by applying silicone resin, cast films and stretched films made of polyester, polypropylene, and polyethylene resins In addition to applying a UV-absorbing layer by applying a paint containing an UV-absorbing agent on one side of the surface, and then applying a silicone resin on the UV-absorbing layer and releasing it, polyester, polypropylene, and polyethylene UV absorber on one side of cast film and stretched film made of An ultraviolet absorbing layer is applied by applying a coating material, a silicone resin is applied to the other surface, and a release treatment can be appropriately selected and used. Different release films can be mentioned.

In addition, as a preferable configuration example, a surface having a configuration in which the present adhesive sheet and a release film are laminated, and a light transmittance at a wavelength of 410 nm or less is 40% or less on the surface of at least one release film The structure formed by laminating a protective film can be mentioned.
By laminating a surface protective film having a light transmittance of 40% or less of light having a wavelength of 410 nm or less on at least one surface of the present pressure-sensitive adhesive sheet laminate, the pressure-sensitive adhesive sheet has a molar extinction coefficient of 10 or more at a wavelength of 405 nm. This is because even if the photopolymerization initiator (C) is contained, it is possible to effectively prevent the photopolymerization from proceeding by irradiation with visible light.
From such a viewpoint, the surface protective film laminated on one or both surfaces of the pressure-sensitive adhesive sheet laminate preferably has a light transmittance of 40% or less for light having a wavelength of 410 nm or less, particularly 30% or less, and more preferably 20%. More preferably, it is as follows.

  Here, as a surface protective film having a light transmittance of 40% or less for light having a wavelength of 410 nm or less, that is, a surface protective film having an action of partially blocking transmission of visible light and ultraviolet light, for example, polyester-based, polypropylene-based A laminated film comprising an ultraviolet absorbing layer formed by applying a re-peelable fine-adhesive resin on one side of a polyethylene cast film or stretched film and applying a paint containing an ultraviolet absorber on the other side. Etc.

<Components for image display device>
Examples of the laminate for constituting an image display device (referred to as “the laminate for constituting an image display device”) laminated via the present adhesive sheet include, for example, a release sheet, a touch panel, an image display panel, a surface protection panel, and a polarizing film. Any of these groups, or a combination of two or more combinations via the present adhesive sheet can be mentioned.

  Specific examples of the laminate for constituting the present image display device include, for example, a release sheet / this adhesive sheet / touch panel, a release sheet / this adhesive sheet / protective panel, a release sheet / this adhesive sheet / image display panel, and an image display. Panel / main adhesive sheet / touch panel, image display panel / main adhesive sheet / protection panel, image display panel / main adhesive sheet / touch panel / main adhesive sheet / protection panel, polarizing film / main adhesive sheet / touch panel, polarizing film / main adhesive Examples of the configuration include a sheet / touch panel / the present adhesive sheet / protective panel. However, it is not limited to these lamination examples.

  The touch panel includes a structure in which a touch panel function is included in a protective panel and a structure in which a touch panel function is included in an image display panel.

<This image display device>
An image display device (referred to as “the present image display device”) can be configured using the laminate for constituting the present image display device.
As this image display device, for example, an image display device such as a liquid crystal display, an organic EL display, an inorganic EL display, electronic paper, a plasma display, and a quantum dot display can be configured.

<Explanation of phrases>
In general, “sheet” refers to a product that is thin by definition in JIS, and whose thickness is small and flat for the length and width. In general, “film” is compared to the length and width. A thin flat product whose thickness is extremely small and whose maximum thickness is arbitrarily limited, and is usually supplied in the form of a roll (Japanese Industrial Standard JISK6900). However, since the boundary between the sheet and the film is not clear and it is not necessary to distinguish the two in terms of the present invention, in the present invention, even when the term “film” is used, the term “sheet” is included and the term “sheet” is used. In some cases, “film” is included.
In addition, the expression “panel” such as an image display panel and a protection panel includes a plate, a sheet, and a film.

In the present specification, when “X to Y” (X and Y are arbitrary numbers) is described, it means “preferably greater than X” or “preferably,” with the meaning of “X to Y” unless otherwise specified. The meaning of “smaller than Y” is also included.
Further, when described as “X or more” (X is an arbitrary number), it means “preferably larger than X” unless otherwise specified, and described as “Y or less” (Y is an arbitrary number). In the case, unless otherwise specified, the meaning of “preferably smaller than Y” is also included.

  Hereinafter, the present invention will be described in more detail with reference to examples and comparative examples. However, the present invention is not limited to these.

[Example 1]
(Meth) acrylic copolymer (A) comprising 15 parts by mass of polymethyl methacrylate macromonomer (Tg 80 ° C.) having a number average molecular weight of 3000, 81 parts by mass of butyl acrylate, and 4 parts by mass of acrylic acid (A-1, mass average molecular weight 300,000) 1 kg of glycerin dimethacrylate (Blenmer GMR, manufactured by NOF Corporation) (B-1) as a crosslinking agent (B), Ezacure KTO46 as a photopolymerization initiator (C) 15 g of (C-1) (manufactured by Lanberti) was added and mixed uniformly to obtain an adhesive composition 1.
The extinction coefficient at 405 nm of the photopolymerization initiator (C-1) was 7.4 × 10 ¹ (ml / g · cm).

  Next, the pressure-sensitive adhesive composition 1 was formed into a sheet shape having a thickness of 100 μm on a peeled polyethylene terephthalate film (Mitsubishi Resin, Diafoil MRV, thickness 100 μm), and then peeled. A pressure-sensitive adhesive sheet laminate 1 was prepared by coating a polyethylene terephthalate film (Mitsubishi Resin, Diafoil MRQ, thickness 75 μm) and laminating release films on both sides of the pressure-sensitive adhesive sheet.

A glass plate 1 with a printed step having a printing height of 40 μm and an opening of 52 mm × 80 mm is prepared on the peripheral edge (long side 3 mm, short side 15 mm) of 658 mm × 110 mm × 0.8 mm thick glass. did. This glass substrate for evaluation is a substitute for an image display device constituent member having a stepped portion and a flat surface portion on the bonding surface.
As a test adherend to be bonded to the glass substrate for evaluation, a polarizing plate (“NWF-KDSEGHC-ST22” manufactured by Nitto Denko Co., Ltd.) as an image display device constituent member is previously placed on a glass plate (54 × 82 mm × What was bonded to the whole surface on one side (t0.5 mm) was produced.

One release film of the pressure-sensitive adhesive sheet laminate 1 was peeled off, and the pressure-sensitive adhesive surface of the exposed pressure-sensitive adhesive sheet was adhered to the polarizing plate surface of the test adherend with a hand roller. Next, the remaining release film is peeled off, and press-bonded under reduced pressure so as to cover the printed stepped portion of the glass with a printed step on the exposed adhesive surface (absolute pressure 5 kPa, temperature 70 ° C., press pressure 0. 04 MPa), autoclave treatment (70 ° C., gauge pressure 0.2 MPa, 20 minutes) was applied and finished.
Next, under a fluorescent lamp (illuminance 3800Lx), the laminate is allowed to stand for 5 hours so that the glass surface with a printed step is on, and the adhesive sheet is irradiated with the light of the fluorescent lamp (visible light), The evaluation laminated body 1 was created.
At this time, the integrated light amount of the irradiated light with a wavelength of 380 nm or less was 0 J / cm ² , and the integrated light amount at a wavelength of 405 nm was about 3.4 J / cm ² .
At this time, the integrated light amount of each wavelength was measured using an integrated light meter (UIT-250, manufactured by USHIO INC.) (The same applies hereinafter).

[Example 2]
Laminated adhesive sheet in the same manner as in Example 1, except that 10 g of 2,2′-dihydroxy-4-methoxybenzophenone (Kemipro Kasei Co., Ltd., Kemisorb 111) (D-1) was further added as the ultraviolet absorber (D). The body 2 and the laminated body 2 for evaluation were created.

[Example 3]
Implemented except using a release film in which a silicone release agent was applied to a PET film with a UV absorber (thickness 100 μm) instead of a polyethylene terephthalate film (diafoil MRV, thickness 100 μm) subjected to a release treatment. In the same manner as in Example 2, an adhesive sheet laminate 3 and an evaluation laminate 3 were prepared.

[Example 4]
On the surface of the polyethylene terephthalate film (diafoil MRV, thickness 100 μm) of the pressure-sensitive adhesive sheet laminate prepared in Example 2, a surface comprising a slightly adhesive layer (5 μm) / polyethylene terephthalate film (25 μm) / ultraviolet absorption layer (3 μm) The slightly adhesive layer surface of the protective film was laminated to prepare an adhesive sheet laminate 4 and an evaluation laminate 4 having a structure of release film / adhesive sheet / release film / surface protective film.

[Comparative Example 1]
The adhesive sheet laminate 5 and the laminate for evaluation were the same as in Example 1 except that 15 g of Ezacure TZT (C-2) was added as a photopolymerization initiator instead of Ezacure KTO46 (C-1). 5 was created.
The extinction coefficient at 405 nm of the photopolymerization initiator (C-2) was less than 10, which was too low to be measured.

[Comparative Example 2]
L as an isocyanate-based crosslinking agent for 1 kg of a pressure-sensitive adhesive solution (manufactured by Soken Chemical Co., Ltd., SK Dyne 1882, solid content concentration: about 17%) made of a commercially available acrylic copolymer (A-2, mass average molecular weight 1.3 million) -45 (manufactured by Soken Chemical Co., Ltd.), 0.5 g of E-5XM (manufactured by Soken Chemical Co., Ltd.) as an epoxy crosslinking agent, and 2,2′-dihydroxy-4-methoxybenzophenone as an ultraviolet absorber (D) (Kemipro Kasei Co., Ltd., Kemisorb 111) (D-1) 10 g was added and mixed uniformly to prepare an adhesive composition 2.

Next, the adhesive composition 2 was applied on a polyethylene terephthalate film (Mitsubishi Resin Co., Ltd., Diafoil MRV, thickness 100 μm) subjected to a release treatment so that the thickness after drying was 50 μm. It was dried at 5 ° C. for 5 minutes to obtain a sheet-like pressure-sensitive adhesive composition having a thickness of 50 μm.
Similarly, on the polyethylene terephthalate film (Mitsubishi Resin, Diafoil MRQ, thickness 75 μm) subjected to the release treatment, the pressure-sensitive adhesive composition 2 was applied so that the thickness after drying was 50 μm. It was dried at 5 ° C. for 5 minutes to obtain a sheet-like pressure-sensitive adhesive composition having a thickness of 50 μm. After laminating these to a thickness of 100 μm, a peeled polyethylene terephthalate film (manufactured by Mitsubishi Plastics, Diafoil MRQ, thickness 75 μm) was coated. This was cured for 7 days at room temperature (23 ° C.) to react with the cross-linking agent, and the pressure-sensitive adhesive sheet laminate 6 was prepared.

  One release film of the pressure-sensitive adhesive sheet laminate 6 was peeled off, and the exposed pressure-sensitive adhesive surface was adhered to the polarizing plate surface of the test adherend with a hand roller. Next, the remaining release film is peeled off, and press-bonded under reduced pressure so as to cover the printed stepped portion of the glass with a printed step on the exposed adhesive surface (absolute pressure 5 kPa, temperature 70 ° C., press pressure 0. 04 MPa), autoclave treatment (70 ° C., gauge pressure 0.2 MPa, 20 minutes) was applied and finished, and an evaluation laminate 6 was prepared.

<Evaluation>
[optical properties]
The PET films on both sides of the pressure-sensitive adhesive sheet laminates 1 to 6 produced in the examples and comparative examples were sequentially peeled, and the pressure-sensitive adhesive sheets were stuck so as to be sandwiched between two soda lime glasses (thickness 0.5 mm). Using a high pressure mercury lamp through a UV cut filter, and visible light irradiation as the accumulated light quantity of the wavelength 405nm is 3000 mJ / cm ² at a wavelength 380nm following integrated light quantity of 5 mJ / cm ² or less, a sample for evaluation optical properties Created.
The light transmittance in a wavelength range of 360 to 430 nm of the prepared test piece was measured with a spectrophotometer (manufactured by Shimadzu Corporation; device name “UV2450”). The results are shown in Table 1.

[Adhesive force]
One release film of the pressure-sensitive adhesive sheet laminates 1 to 6 prepared in Examples and Comparative Examples was peeled off, and a polyethylene terephthalate film (manufactured by Toyobo Co., Ltd .; trade name “Cosmo Shine A4300”, thickness 100 μm) was used as a backing film. Roll pressing was performed with a roller. This was cut into a strip of 10 mm width × 100 mm length, and the remaining adhesive film was peeled off and the exposed adhesive surface was roll-bonded to soda lime glass using a hand roller. After autoclaving (70 ° C., gauge pressure 0.2 MPa, 20 minutes) and finishing and sticking, using a high-pressure mercury lamp through a UV cut filter, the integrated light quantity at a wavelength of 380 nm or less is 5 mJ / cm ² or less. Visible light was irradiated so that the integrated light quantity with a wavelength of 405 nm would be 3000 mJ / cm < ² >, and the adhesive force measurement sample was created. While pulling the backing film at an angle of 180 ° at a peeling speed of 60 mm / min, the pressure-sensitive adhesive sheet was peeled from the glass, the tensile strength was measured with a load cell, and the 180 ° peel strength of the pressure-sensitive adhesive sheet to the glass was measured. Is shown as “Glass Adhesive Strength”. The results are shown in Table 1.

[Gel fraction]
One release film of the pressure-sensitive adhesive sheet laminates 1 to 6 prepared in Examples and Comparative Examples is peeled off, and left to stand for 5 hours under a fluorescent lamp (illuminance 3800 Lx) from the exposed pressure-sensitive adhesive side. Of light (visible light). The integrated light quantity of the irradiated light at a wavelength of 405 nm was about 3400 mJ / cm ² .

About the adhesive sheet laminated bodies 1-6 before and behind a light irradiation process, the gel fraction of the adhesive material was calculated | required with the following method. The results are shown in Table 1.
1) The pressure-sensitive adhesive composition is weighed (W1) and wrapped in a pre-weighed SUS mesh (W0).
2) The SUS mesh is immersed in 100 mL of ethyl acetate for 24 hours.
3) Take out the SUS mesh and dry at 75 ° C. for 4 and a half hours.
4) The weight (W2) after drying is determined, and the gel fraction of the pressure-sensitive adhesive composition is measured from the following formula.
Gel fraction (%) = 100 × (W2−W0) / W1

[Unevenness absorption]
Regarding the evaluation laminates 1 to 6 created in the examples and comparative examples, the irregularity absorbency “good” was observed in the vicinity of the printing step, and bubbles were observed in the vicinity of the printing step. Was determined to be uneven absorption “× (poor)”. The results are shown in Table 1.

[Heat-resistant]
The laminates for evaluation 1 to 6 prepared in Examples and Comparative Examples were cured at 85 ° C. for 6 hours, and those that had no change in appearance without foaming or the like had heat resistance “good”, foaming and peeling. What was seen was judged to be heat resistant “× (poor)”. The results are shown in Table 1.

  Exfoliated polyethylene terephthalate film used in Example 2 (Mitsubishi Resin, Diafoil MRV, thickness 100 μm, referred to as “film A”), polyethylene terephthalate film containing an ultraviolet absorber used in Example 3 ( Wavelength range of 380 to 450 nm for a release film (referred to as “film B”) coated with a silicone release agent on a thickness of 100 μm) and a surface protective film (referred to as “film C”) used in Example 4 The light transmittance was measured with a spectrophotometer (manufactured by Shimadzu Corporation; instrument name “UV2450”). The results are shown in Table 2.

The pressure-sensitive adhesive sheet laminate 2 (Example 2), the pressure-sensitive adhesive sheet laminate 3 (Example 3), and the pressure-sensitive adhesive sheet laminate 4 (Example 4) were respectively allowed to stand with the films A, B, and C side up. . And the light of the fluorescent lamp (illuminance 1100Lx) was irradiated from the said film A, B, C side for 7 days. The integrated light quantity of the irradiated light at a wavelength of 405 nm was about 43000 mJ / cm ² .

  About the adhesive sheet laminated body 2 (Example 2) before and behind light irradiation process, the adhesive sheet laminated body 3 (Example 3), and the adhesive sheet laminated body 4 (Example 4), the gel fraction of an adhesive material is as follows. Asked. The results are shown in Table 2.

1) The pressure-sensitive adhesive composition is weighed (W1) and wrapped in a pre-weighed SUS mesh (W0).
2) The SUS mesh is immersed in 100 mL of ethyl acetate for 24 hours.
3) Take out the SUS mesh and dry at 75 ° C. for 4 and a half hours.
4) The weight (W2) after drying is determined, and the gel fraction of the pressure-sensitive adhesive composition is measured from the following formula.
Gel fraction (%) = 100 × (W2−W0) / W1

  Regarding storage stability, the change in gel fraction was less than 5 points before and after irradiation with a fluorescent lamp, “Good”, and the gel fraction increased by 5 points or more after light irradiation, “× (poor) Was determined. The results are shown in Table 2.

The laminated body for image display apparatus construction created in Examples 1 to 4 can obtain a laminated body with high bonding reliability without irradiating the adherend with ultraviolet rays by curing visible light at the time of bonding. It was.
Since Comparative Example 1 used a photopolymerization initiator having a molar extinction coefficient at a wavelength of 405 nm of less than 10, that is, no photopolymerization initiator having an extinction coefficient at a wavelength of 405 nm of 10 or more was used, it was irradiated with visible light. However, the adhesive material was not cured, and the adhesive strength and reliability after bonding were poor.
Comparative Example 2 is a pressure-sensitive adhesive sheet obtained by crosslinking a pressure-sensitive adhesive composition by thermal crosslinking. Since it is a general pressure-sensitive adhesive sheet that does not have photo-curing properties, it is difficult to achieve both the unevenness absorbability and durability at the time of bonding, and floating occurs in the vicinity of the printing step, resulting in poor bonding quality.

  In Example 3, a PET film containing an ultraviolet absorber is used as the polyethylene terephthalate film subjected to the release treatment. Thereby, it was possible to prevent the photocuring reaction of the pressure-sensitive adhesive composition from proceeding before being bonded to the image display device constituting member, and to obtain a pressure-sensitive adhesive sheet laminate excellent in storage stability.

  In Example 4, a surface protective film having an ultraviolet absorbing layer is laminated on the surface of the release film. Thereby, it can suppress that the photocuring reaction of an adhesive material composition advances in the stage before bonding to the member for image display apparatus structure, and it can be set as the adhesive sheet laminated body excellent in storage stability. did it.

  From the above-mentioned Examples / Comparative Examples and the test results conducted by the present inventors, the (meth) acrylic copolymer (A), the crosslinking agent (B), and the extinction coefficient at a wavelength of 405 nm are 10 or more. After laminating two image display device constituent members via a double-sided pressure-sensitive adhesive sheet comprising a pressure-sensitive adhesive composition containing a photopolymerization initiator (C), the image display device from the outside of at least one image display device constituent member If the double-sided pressure-sensitive adhesive sheet is irradiated with light that contains at least light having a wavelength of 405 nm and does not substantially contain light having a wavelength of 380 nm or less through the constituent member, the double-sided pressure-sensitive adhesive sheet is cured by visible light crosslinking. Then, after first sticking using the pressure-sensitive adhesive sheet, it can be further photocured and secondarily stuck, so that the step absorbability when the bonding surface of the bonding member has unevenness and the resistance after bonding Departure It was possible to confirm that it is possible to achieve both reliability.

  At this time, although the extinction coefficient (wavelength 405 nm) of the photopolymerization initiator (C) used in Examples 1 to 4 was 74, if the extinction coefficient was 10 or more, the photopolymerization initiator ( By adjusting the content of C), it is sufficiently sensitive to light having a wavelength in the visible light region, and the double-sided pressure-sensitive adhesive sheet can be cured by crosslinking with visible light, so that the light used in Examples 1 to 4 It can be considered that the same effect as that of the polymerization initiator (C) can be obtained. From such a viewpoint, the extinction coefficient (wavelength 405 nm) of the photopolymerization initiator (C) may be 10 or more, preferably 15 or more, and particularly preferably 25 or more.

Claims (9)

A method for producing a laminate for constituting an image display device comprising a constitution in which image display device constituting members are laminated via a double-sided pressure-sensitive adhesive sheet, comprising at least the following steps (1) to (3):
The light containing at least light having a wavelength of 405 nm and substantially not containing light having a wavelength of 380 nm or less is at least one or two selected from the sun, fluorescent lamp, LED, organic EL, inorganic EL, and light emitting module for image display device Ri light der emitted from the light source consisting of seeds or combinations,
The image display device components, characterized in der Rukoto having a property of absorbing ultraviolet light, a method of manufacturing an image display device configured for laminate.
(1) Double-sided adhesive from an adhesive composition containing a (meth) acrylic copolymer (A), a crosslinking agent (B), and a photopolymerization initiator (C) having an absorption coefficient of 10 or more at a wavelength of 405 nm. A step of producing a sheet.
(2) The process of laminating | stacking two image display apparatus structural members through the double-sided adhesive sheet before photocuring.
(3) After laminating two image display device constituting members through the double-sided adhesive sheet, the light containing at least a wavelength of 405 nm is included through the image display device constituting member from the outside of at least one image display device constituting member. And a step of irradiating the double-sided pressure-sensitive adhesive sheet with light substantially free of light having a wavelength of 380 nm or less to cause the double-sided pressure-sensitive adhesive sheet to be crosslinked by visible light and curing.   The double-sided PSA sheet before laminating the image display device constituting member has a configuration in which a release film having a wavelength of 410 nm or less and a light transmittance of 40% or less is laminated on one or both of the double-sided PSA sheets. The manufacturing method of the laminated body for image display apparatus structures of Claim 1 characterized by the above-mentioned.   The double-sided pressure-sensitive adhesive sheet before laminating the image display device constituting member has a structure in which a pressure-sensitive adhesive sheet and a release film are laminated, and light transmission with a wavelength of 410 nm or less is provided on the surface of at least one release film. The method for producing a laminate for constituting an image display device according to claim 1, wherein the laminate comprises a surface protection film having a rate of 40% or less. A method of manufacturing a double-sided pressure-sensitive adhesive sheet through the image display device component image display device configured for laminate having a structure obtained by laminating, have at least the following steps (1) to (3),
The image display device component members, a method of manufacturing an image display device constituting a laminate for, characterized in der Rukoto having a property of absorbing ultraviolet light.
(1) Double-sided adhesive from an adhesive composition containing a (meth) acrylic copolymer (A), a crosslinking agent (B), and a photopolymerization initiator (C) having an absorption coefficient of 10 or more at a wavelength of 405 nm. A step of producing a sheet.
(2) After the two image display device components via the double-sided pressure-sensitive adhesive sheet before photocuring and product layer, or heating with laminated, so as to soften the double-sided pressure-sensitive adhesive sheet.
(3) After laminating two image display device constituting members through the double-sided adhesive sheet, the light containing at least a wavelength of 405 nm is included through the image display device constituting member from the outside of at least one image display device constituting member. And a step of irradiating the double-sided pressure-sensitive adhesive sheet with light substantially free of light having a wavelength of 380 nm or less to cause the double-sided pressure-sensitive adhesive sheet to be crosslinked by visible light and curing.   The method for manufacturing a laminate for constituting an image display device according to claim 4, wherein one or both of the image display device constituting members are heated to heat the double-sided pressure-sensitive adhesive sheet.   The (meth) acrylic copolymer (A) is an acrylic copolymer composed of a graft copolymer having a macromonomer as a branch component. A method for producing a laminate for constituting an image display device.   The method for producing a laminate for constituting an image display device according to any one of claims 1 to 6, wherein the pressure-sensitive adhesive composition further contains an ultraviolet absorber (D).   The image display device constituent member is a laminate composed of any one type or a combination of two or more types of groups consisting of a touch panel, an image display panel, a surface protection panel, and a polarizing film. 8. A method for producing a laminate for constituting an image display device according to any one of 7 above. An image display apparatus is manufactured using the laminated body for image display apparatus structures manufactured by the manufacturing method in any one of Claims 1-8, The manufacturing method of the image display apparatus characterized by the above-mentioned.