JP2017197622A - Double-sided adhesive sheet with decorative layer and laminate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a double-sided adhesive sheet with a decorative layer, which has both step followability and outgassing resistance.SOLUTION: The present invention relates to a double-sided adhesive sheet with a decorative layer, which includes: a substrate layer having a first surface and a second surface opposite to the first surface and provided with a decorative layer on a part of the first surface; a first adhesive layer with a thickness of 5 μm or more and 75 μm or less on the second surface side; and a second adhesive layer on the first surface side. The storage modulus G' (1 Hz) of the second adhesive layer at a measurement temperature of 25°C and a frequency of 1 Hz is 1×10Pa or more and 5×10Pa or less.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a double-sided pressure-sensitive adhesive sheet with a decorative layer and a laminate.

  In recent years, display devices such as a liquid crystal display (LCD) and input devices used in combination with a display device such as a touch panel have been widely used in various fields. In the manufacture of these display devices and input devices, a transparent double-sided pressure-sensitive adhesive sheet is used for the purpose of bonding optical members. For example, a double-sided pressure-sensitive adhesive sheet is used for bonding two members such as a display device such as a liquid crystal display (LCD) and a cover panel arranged on the front side (view side) thereof.

  2. Description of the Related Art In mobile phone terminal devices such as smartphones, frame printing is performed to conceal electrical circuits and the like inside the devices. In such a case, a decorative layer is often provided at the peripheral edge of the back surface of the cover panel, and the adhesive layer bonded to the back surface side of the cover panel has a property that can follow the steps of the decorative layer. It is demanded. In addition, when the cover panel is made of resin, the adhesive layer bonded to the back side of the cover panel needs to have an adhesive force and a cohesive force that can counteract the gas pressure of outgas generated from the resin panel. is there. As described above, the pressure-sensitive adhesive layer may be required to have both step following ability and outgas resistance, and as means for achieving these problems, a post-curing pressure-sensitive adhesive layer by ultraviolet irradiation has been proposed. (For example, patent document 1 etc.).

  In recent years, a decorative print layer has been provided on an internal component member in response to demands for thinness of a mobile phone terminal device and versatile design. For example, Patent Document 2 discloses a pressure-sensitive adhesive sheet with a decorative print layer. Here, a hard coat layer is provided on one surface of a base material layer, and decorative print is provided on the other surface of the base material layer. A pressure-sensitive adhesive sheet provided with a layer and further having a pressure-sensitive adhesive layer provided on the surface is disclosed. Patent Document 3 discloses a pressure-sensitive adhesive sheet in which a decorative print layer is provided between a first pressure-sensitive adhesive layer and a second pressure-sensitive adhesive layer provided on the back surface of a cover panel.

International Publication No. 2012/032995 JP 2011-93977 A JP 2012-226111 A

  When using an ultraviolet ray post-curing pressure-sensitive adhesive layer as described in Patent Document 1, the bonding application is limited to bonding an adherend that transmits ultraviolet rays. For example, the ultraviolet post-curing pressure-sensitive adhesive layer described in Patent Document 1 cannot be applied when an adherend that does not transmit ultraviolet light is bonded.

  Further, in the pressure-sensitive adhesive sheet described in Patent Documents 2 and 3, the outgas resistance is insufficient, and when a resin cover panel or the like is used as an adherend, the influence of foaming due to outgas is large. The problem remained.

  Therefore, in order to solve such a problem of the prior art, the present inventors are a double-sided pressure-sensitive adhesive sheet that can be applied to bonding of an adherend that does not transmit ultraviolet rays, and has a step following ability and an outgas resistance. The study was advanced for the purpose of providing a double-sided pressure-sensitive adhesive sheet with a decorative layer that has both of these properties.

As a result of intensive studies to solve the above problems, the present inventors have provided a pressure-sensitive adhesive layer having predetermined physical properties on each surface of a base material layer having a decorative layer, thereby providing a step following property. It has been found that a double-sided pressure-sensitive adhesive sheet with a decorative layer having both properties of outgas resistance can be obtained. The present inventors have found that such a double-sided pressure-sensitive adhesive sheet with a decorative layer can also be applied to bonding of adherends that do not transmit ultraviolet rays, and have completed the present invention.
Specifically, the present invention has the following configuration.

[1] A base material layer having a first surface and a second surface opposite to the first surface, the base material layer having a decorative layer on a part of the first surface, It has a first pressure-sensitive adhesive layer having a thickness of 5 μm or more and 75 μm or less on the second surface side, a second pressure-sensitive adhesive layer on the first surface side, a measurement temperature of the second pressure-sensitive adhesive layer of 25 ° C., and a frequency of 1 Hz The double-sided pressure-sensitive adhesive sheet with a decorative layer having a storage elastic modulus G ′ (1 Hz) of 1 × 10 ⁴ Pa or more and 5 × 10 ⁵ Pa or less.
[2] The double-sided pressure-sensitive adhesive sheet with a decorative layer according to [1], wherein the base material layer has a multilayer structure.
[3] The double-sided pressure-sensitive adhesive sheet with a decorative layer according to [1] or [2], wherein the base material layer includes a base resin layer and at least one layer selected from a primer layer and a hard coat layer.
[4] The double-sided pressure-sensitive adhesive sheet with a decorative layer according to any one of [1] to [3], wherein the first pressure-sensitive adhesive layer contains an acrylic polymer.
[5] The double-sided pressure-sensitive adhesive sheet with a decorative layer according to any one of [1] to [4], wherein the second pressure-sensitive adhesive layer contains an acrylic polymer.
[6] The double-sided pressure-sensitive adhesive sheet with a decorative layer according to any one of [1] to [5], wherein the first pressure-sensitive adhesive layer is bonded to the surface resin layer.
[7] The double-sided pressure-sensitive adhesive sheet with a decorative layer according to any one of [1] to [6], wherein the second pressure-sensitive adhesive layer is bonded to a display device.
[8] The double-sided pressure-sensitive adhesive sheet with a decorative layer according to any one of [1] to [7], a surface resin layer laminated on the first pressure-sensitive adhesive layer, and a layer on the second pressure-sensitive adhesive layer And a display device.

  ADVANTAGE OF THE INVENTION According to this invention, the double-sided adhesive sheet with a decorating layer which has the property of both level | step difference followability and outgas resistance can be obtained. The double-sided pressure-sensitive adhesive sheet with a decorative layer of the present invention is also useful for bonding adherends that do not transmit ultraviolet rays.

FIG. 1 is a schematic cross-sectional view illustrating one embodiment of a double-sided pressure-sensitive adhesive sheet with a decorative layer of the present invention. FIG. 2 is a schematic cross-sectional view illustrating one embodiment of the double-sided pressure-sensitive adhesive sheet with a decorative layer of the present invention. FIG. 3 is a schematic cross-sectional view illustrating a configuration of a laminate formed by bonding an adherend using the double-sided pressure-sensitive adhesive sheet with a decorative layer of the present invention.

  Hereinafter, the present invention will be described in detail. The description of the constituent elements described below may be made based on representative embodiments and specific examples, but the present invention is not limited to such embodiments.

(Double-sided adhesive sheet with decorative layer)
The present invention relates to a double-sided pressure-sensitive adhesive sheet with a decorative layer having a base material layer including a decorative layer, a first pressure-sensitive adhesive layer, and a second pressure-sensitive adhesive layer. The double-sided pressure-sensitive adhesive sheet with a decorative layer of the present invention is a base material layer having a first surface and a second surface opposite to the first surface, and the decorative layer is partially formed on the first surface. It has a base material layer provided. Moreover, it has the 1st adhesive layer whose thickness is 5 micrometers or more and 75 micrometers or less on the 2nd surface side of a base material layer. Furthermore, it has a 2nd adhesive layer in the 1st surface side of a base material layer. The storage elastic modulus G ′ (1 Hz) at a measurement temperature of 25 ° C. and a frequency of 1 Hz of the second pressure-sensitive adhesive layer is 1 × 10 ⁴ Pa or more and 5 × 10 ⁵ Pa or less.

  In the present invention, the decorative layer is provided on one surface (first surface) of the base material layer. And since the decoration layer is provided in a part on the 1st surface, the part in which the decoration layer is not provided exists on the 1st surface.

Since the double-sided pressure-sensitive adhesive sheet with a decorative layer of the present invention has the above-described configuration, it has both the properties of both step following ability and outgas resistance. The 1st adhesive layer of this invention exhibits the outstanding outgas resistance, and the 2nd adhesive layer can track the level | step difference which a decoration layer and a to-be-adhered body have. For this reason, when a to-be-adhered body is bonded using the double-sided adhesive sheet of this invention, and a laminated body is formed, it can suppress that a bubble generate | occur | produces in a laminated body.
Moreover, the double-sided pressure-sensitive adhesive sheet with a decorative layer of the present invention does not require a post-curing step by ultraviolet irradiation or the like. For this reason, it can be preferably applied even when a resin cover panel that does not transmit ultraviolet rays is used as the surface cover layer. The double-sided pressure-sensitive adhesive sheet with a decorative layer of the present invention is characterized in that it exhibits both the step following property and the outgas resistance without passing through a post-curing step. Furthermore, when the double-sided pressure-sensitive adhesive sheet with a decorative layer of the present invention is used, a post-curing process is not required, so that the bonding process with the adherend can be simplified.

  FIG. 1 is a schematic cross-sectional view illustrating one embodiment of a double-sided pressure-sensitive adhesive sheet with a decorative layer of the present invention. As FIG. 1 shows, the double-sided adhesive sheet 100 with a decoration layer has the base material layer 10 which has the decoration layer 5 in one surface (1st surface). And the double-sided adhesive sheet 100 with a decoration layer is one surface of the base material layer 10, Comprising: Thickness is 5 micrometers or more and 75 micrometers on the surface (2nd surface) side opposite to the surface in which the decoration layer 5 was provided. It has the following first pressure-sensitive adhesive layer 12. Moreover, the double-sided pressure-sensitive adhesive sheet 100 with a decorative layer has a second pressure-sensitive adhesive layer 14 on the surface (first surface) side of the base material layer 10 on which the decorative layer 5 is provided.

  The total thickness of the double-sided pressure-sensitive adhesive sheet with a decorative layer of the present invention is preferably 150 μm or more, more preferably 200 μm or more, further preferably 300 μm or more, and particularly preferably 500 μm or more. . Moreover, it is preferable that the whole thickness of the double-sided adhesive sheet with a decoration layer is 10 mm or less, and it is more preferable that it is 5 mm or less.

  In the double-sided pressure-sensitive adhesive sheet with a decorative layer of the present invention, the first pressure-sensitive adhesive layer is preferably bonded to the surface cover layer. Examples of the surface cover layer include a glass plate and a resin layer. Especially, it is preferable that the 1st adhesive layer of the double-sided adhesive sheet of this invention is bonded by the resin layer (surface resin layer). Since the 1st adhesive layer is excellent in outgas resistance, even if it is a case where a surface cover layer is a resin layer, generation | occurrence | production of the bubble after bonding can be suppressed.

  Moreover, in the double-sided pressure-sensitive adhesive sheet with a decorative layer of the present invention, the second pressure-sensitive adhesive layer is preferably bonded to an optical member. Examples of the optical member include a display device, and the display device is a liquid crystal display device (liquid crystal display panel), a plasma display device (plasma display panel), an organic electroluminescence display device (organic EL panel), or the like. Preferably there is.

(Base material layer)
The base material layer includes a resin. Examples of the resin contained in the base material layer include polyolefin resins such as polyethylene resin and polypropylene resin, polyester resins such as polyethylene terephthalate resin, polyethylene naphthalate resin, and polybutylene terephthalate resin, polyvinyl chloride resin, polystyrene resin, and polyurethane resin. And various synthetic resins such as polycarbonate resin, polyamide resin, polyimide resin, fluorine resin, and cycloolefin polymer resin. Among these, at least one selected from polyethylene terephthalate resin (PET resin) and cycloolefin polymer resin (COP resin) is preferably used, and polyethylene terephthalate resin (PET resin) is particularly preferably used.

  The thickness of the base material layer is preferably 50 μm or more, more preferably 60 μm or more, and further preferably 70 μm or more. Further, the thickness of the base material layer is preferably 500 μm or less, more preferably 400 μm or less, and further preferably 300 μm or less.

  In the double-sided pressure-sensitive adhesive sheet with a decorative layer of the present invention, the base material layer may have a multilayer structure. When the base material layer has a multilayer structure, the base material layer preferably has, for example, a base resin layer and a functional layer.

  FIG. 2 is a schematic cross-sectional view illustrating a configuration of the double-sided pressure-sensitive adhesive sheet with a decorative layer according to the present invention, in which the base material layer has a multilayer structure. As FIG. 2 shows, the double-sided adhesive sheet 100 with a decoration layer has the base material layer 10 which has the decoration layer 5 in one surface. Here, it is preferable that the base material layer 10 has the base resin layer 10a and the functional layer 10b. In FIG. 2, the functional layer 10 b is arranged on the decorative layer 5 side, but the arrangement of the base resin layer 10 a and the functional layer 10 b is not particularly limited, and is based on the decorative layer 5 side. The material resin layer 10a may be disposed. In addition, a plurality of functional layers 10b may be provided. In this case, the plurality of functional layers 10b may be provided on one surface side of the base resin layer 10a, and on both surfaces of the base resin layer 10a. It may be provided.

  Examples of the functional layer 10b include at least one layer selected from a primer layer and a hard coat layer. That is, the base material layer preferably includes a base resin layer and at least one layer selected from a primer layer and a hard coat layer.

<Primer layer>
The primer layer is preferably an undercoat layer of the base resin layer. By providing the primer layer, the influence of the solvent on the base resin layer can be minimized when a solvent-type pressure-sensitive adhesive layer is used. In addition, when the base material layer has a multilayer structure of the base resin layer and the primer layer, the thickness of the base material resin layer is larger than the thickness of the primer layer. Can do.

  As resin which comprises a primer layer, an epoxy resin can be mentioned, for example. The epoxy resin can be either a one-component curable type or a two-component curable type. A water-soluble epoxy resin is particularly preferably used. Examples of water-soluble epoxy resins include polyamide epoxy resins. The polyamide epoxy resin is obtained by reacting epichlorohydrin with a polyamide polyamine obtained by reacting a polyalkylene polyamine such as diethylenetriamine or triethylenetetramine with a dicarboxylic acid such as adipic acid.

  When a water-soluble epoxy resin is used as the resin for forming the primer layer, another water-soluble resin such as a polyvinyl alcohol resin may be mixed in order to further improve the coatability. Polyvinyl alcohol resins are modified such as partially saponified polyvinyl alcohol and fully saponified polyvinyl alcohol, as well as carboxyl group-modified polyvinyl alcohol, acetoacetyl group-modified polyvinyl alcohol, methylol group-modified polyvinyl alcohol, and amino group-modified polyvinyl alcohol. Polyvinyl alcohol resin may be used.

  The resin constituting the primer layer is preferably used in a state dissolved in a solvent. As a solvent used in this case, water is preferably used, but an organic solvent may be used. Organic solvents include aromatic hydrocarbons such as benzene, toluene and xylene, ketones such as acetone, methyl ethyl ketone and methyl isobutyl ketone, esters such as ethyl acetate and isobutyl acetate, chlorination such as methylene chloride, trichloroethylene and chloroform. Common organic solvents such as hydrocarbons, alcohols such as ethanol, 1-propanol, 2-propanol, and 1-butanol can also be used.

<Hard coat layer>
In this invention, it is preferable that a hard-coat layer is a layer provided in order to improve decorating printing aptitude. Moreover, a hard-coat layer can also improve the intensity | strength and durability of a double-sided adhesive sheet with a decoration layer.

  The hard coat layer preferably contains a hard component for imparting hardness. Examples of the hard component include a crosslinked polymer. Examples of the crosslinked polymer include a monofunctional monomer polymer and a polyfunctional monomer polymer. The polyfunctional monomer polymer is preferably a polymer of a polymerizable monomer containing a trifunctional or higher polyfunctional monomer, more preferably a polymer of a polymerizable monomer containing a tetrafunctional or higher polyfunctional monomer. For example, a copolymer of a mixed monomer of a trifunctional or higher polyfunctional monomer and a bifunctional monomer can be preferably exemplified. In addition, an oligomer is also contained in the monomer here.

Although the kind of monomer which can be used in order to obtain a crosslinked polymer is not restrict | limited in particular, For example, an acrylic monomer etc. can be illustrated preferably. Specifically, dipropylene glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, tripropylene glycol di (meth) acrylate, polyethylene glycol (weight average molecular weight 600) di (meth) acrylate, propylene Bifunctional (meta) such as oxide-modified neopentyl glycol di (meth) acrylate, modified bisphenol A di (meth) acrylate, tricyclodecane dimethanol di (meth) acrylate, polyethylene glycol (weight average molecular weight 400) di (meth) acrylate ) Acrylate, pentaerythritol tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethylolpropane ethoxytri (meth) acrylate, polyether tri (meth) acrylate Relate, trifunctional (meth) acrylate such as glycerin propoxytri (meth) acrylate, pentaerythritol tetra (meth) acrylate, pentaerythritol ethoxytetra (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, propionic acid modified dipentaerythritol Examples include tetra- or higher functional (meth) acrylates such as penta (meth) acrylate, dipentaerythritol monohydroxypenta (meth) acrylate, and dipentaerythritol hexa (meth) acrylate.
The monomer or oligomer of the organic compound having a polymerizable unsaturated group may be thermosetting or active energy ray curable.

  The hard coat layer may contain a flexible component. Examples of the flexible component include tricyclodecanemethylol di (meth) acrylate, ethylene oxide-modified di (meth) acrylate of bisphenol F, ethylene oxide-modified di (meth) acrylate of bisphenol A, ethylene oxide-modified di (meth) acrylate of isocyanuric acid ( Bifunctional (meth) acrylates such as (meth) acrylate, polypropylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, propylene oxide modified tri (meth) acrylate of trimethylpropane, trimethyl Trifunctional (meth) acrylates such as propane ethylene oxide modified tri (meth) acrylate, urethane (meth) acrylate, polyester (meth) acrylate DOO, polyether (meth) acrylate.

  The hard coat layer may contain inorganic particles and / or organic particles. When inorganic particles and / or organic particles are contained, curing shrinkage is preferably suppressed. Examples of the inorganic particles include inorganic oxide particles such as silicon dioxide particles, titanium dioxide particles, zirconium oxide particles, aluminum oxide particles, tin dioxide particles, antimony pentoxide particles, and antimony trioxide particles. Examples of the organic particles include resin particles such as acrylic resin, polystyrene, polysiloxane, melamine resin, benzoguanamine resin, polytetrafluoroethylene, cellulose acetate, polycarbonate, and polyamide.

  When inorganic particles are used, reactive inorganic oxide particles treated with a coupling agent may be used. When organic particles are used, reactive organic oxide particles treated with a coupling agent may be used. By treating with a coupling agent, the bonding strength with the acrylic polymer can be increased.

  Examples of the coupling agent include γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, and γ-mercaptopropyltrimethoxy. Examples thereof include silane, γ-aminopropyltriethoxysilane, and γ-aminopropyltriethoxyaluminum. These may be used individually by 1 type and may use 2 or more types together.

  The thickness of the hard coat layer is not particularly limited, but is preferably, for example, 0.5 μm or more, more preferably 1.0 μm or more, and further preferably 2.0 μm or more. Further, the thickness of the hard coat layer is preferably 100 μm or less, and more preferably 50 μm or less.

(Decoration layer)
A decorative layer is provided on one surface of the base material layer. The decorative layer may be a decorative print layer provided by printing. Examples of the printing method for configuring the decorative printing layer include gravure printing and screen printing. The decorative layer may be a frame-shaped electrode concealed print layer or a printed pattern having design properties.

  There is no restriction | limiting in particular as a coating material for comprising a decorating printing layer, A well-known coating material can be used. Examples of the paint include ultraviolet curable ink and oxidation polymerization type ink.

  The thickness of the decorative layer is preferably 5 μm or more, more preferably 7 μm or more, and further preferably 10 μm or more. Moreover, it is preferable that the thickness of a decoration layer is 50 micrometers or less, It is more preferable that it is 30 micrometers or less, It is further more preferable that it is 25 micrometers or less. In the present invention, the thickness of the decorative layer can be made larger than 50 μm as necessary. In this case, it is possible to follow the step between the decorative layer and the base material layer by appropriately adjusting the thickness of the second pressure-sensitive adhesive layer.

(First adhesive layer)
A 1st adhesive layer is a layer provided in the 2nd surface side of a base material layer. The second surface of the base material layer is a surface on the side where the decorative layer is not provided.

  The thickness of the first pressure-sensitive adhesive layer is 5 μm or more and 75 μm or less. The thickness of the 1st adhesive layer should just be 5 micrometers or more, and it is preferable that it is 10 micrometers or more. Moreover, the thickness of the 1st adhesive layer should just be 75 micrometers or less, it is preferable that it is 60 micrometers or less, and it is more preferable that it is 50 micrometers or less. By setting the thickness of the first pressure-sensitive adhesive layer within the above range, the outgas resistance can be effectively improved. In the present invention, even when the first pressure-sensitive adhesive layer is bonded to a resin cover panel or the like, excellent outgas resistance can be exhibited, and generation of bubbles can be suppressed.

  The first pressure-sensitive adhesive layer is preferably formed from a first pressure-sensitive adhesive composition containing a base polymer as a main component. In the present specification, the “main component” refers to a component contained in an amount of 50% by mass or more based on the total mass of the first pressure-sensitive adhesive composition.

  The base polymer is preferably one having transparency to the extent that visibility is not lowered. Specifically, the base polymer preferably contains at least one selected from an acrylic polymer, a rubber polymer, a silicon polymer, a urethane polymer, and a polyester polymer. Among them, the base polymer preferably contains at least one selected from an acrylic polymer, a rubber polymer, and a silicon polymer, and more preferably contains an acrylic polymer. That is, the first pressure-sensitive adhesive layer preferably contains an acrylic polymer.

<Acrylic polymer>
As an acrylic polymer, a copolymer containing an acrylic monomer unit (a2) having a non-crosslinkable (meth) acrylic acid ester unit (a1) as a main component and having a crosslinkable functional group is used. It is preferable. In the present specification, the “unit” is a repeating unit (monomer unit) constituting the polymer.

As the non-crosslinkable (meth) acrylic acid ester unit (a1) constituting the acrylic polymer, for example, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, (Meth) acrylic such as isobutyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, octyl (meth) acrylate, isooctyl (meth) acrylate, isononyl (meth) acrylate, lauryl (meth) acrylate, isostearyl (meth) acrylate Examples include acid alkyl ester monomers. Two or more of these may be used in combination as required.
In the present invention, “(meth) acrylate” means containing both “acrylate” and “methacrylate”, and “(meth) acrylic acid” means “acrylic acid” and “methacrylic acid”. Is meant to include both.

  Examples of the acrylic monomer unit (a2) having a crosslinkable functional group include (meth) acrylic acid, maleic acid, maleic anhydride, itaconic acid, fumaric acid, fumaric anhydride and other carboxyl group-containing monomers, 2- Hydroxyl-containing monomers such as hydroxyethyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, polyethylene glycol (meth) acrylate, (meth) acrylamide, morpholyacrylamide, N , N-dimethylaminoethyl acrylate, N-tert-butylaminoethyl acrylate and other amino group-containing (meth) acrylic acid esters, glycidyl (meth) acrylate and other epoxy groups. Two or more of these may be used in combination as required.

  The acrylic polymer has a monomer unit other than the non-crosslinkable (meth) acrylic acid ester unit (a1) and the acrylic monomer unit (a2) having a crosslinkable functional group, if necessary. May be. Any other monomer may be used as long as it is copolymerizable with a non-crosslinkable (meth) acrylic acid ester and an acrylic monomer having a crosslinkable functional group. Examples of other monomers include (meth) acrylonitrile, vinyl acetate, styrene, vinyl chloride, vinyl pyrrolidone, vinyl pyridine and the like.

  The weight average molecular weight of the acrylic polymer is preferably from 100,000 to 2,000,000, more preferably from 300,000 to 1,500,000. By setting the weight average molecular weight within the above range, sufficient durability and flexibility can be ensured. The weight average molecular weight of the acrylic polymer is a value before being crosslinked with a crosslinking agent. The weight average molecular weight is a value determined by size exclusion chromatography (SEC) and determined on a polystyrene basis.

The weight average molecular weight of the acrylic polymer can also be measured by gel permeation chromatography (GPC). In this case, the measurement conditions of gel permeation chromatography (GPC) are as follows.
Solvent: tetrahydrofuran (THF)
Column: Shodex KF801, KF803L, KF800L, KF800D (used by connecting four Showa Denko Co., Ltd.)
Column temperature: 40 ° C
Sample concentration: 0.5% by mass
Detector: RI-2031plus (manufactured by JASCO)
Pump: RI-2080plus (manufactured by JASCO)
Flow rate (flow rate): 0.8 ml / min
Injection volume: 10 μl
Calibration curve: Standard polystyrene Shodex standard polystyrene (manufactured by Showa Denko KK) Mw = 1320 to 2500,000 calibration curves with 10 samples are used.

  When polymerizing an acrylic polymer, for example, a solution polymerization method can be applied. Examples of the solution polymerization method include an ionic polymerization method and a radical polymerization method. Examples of the solvent used at that time include tetrahydrofuran, chloroform, ethyl acetate, toluene, hexane, acetone, methyl ethyl ketone, and the like.

When the 1st adhesive composition contains the copolymer using the monomer which has a functional group, it is preferable to contain a crosslinking agent. Thereby, a crosslinking reaction can be promoted. Examples of the crosslinking agent include isocyanate compounds, epoxy compounds, oxazoline compounds, aziridine compounds, metal chelate compounds, butylated melamine compounds, and these may be used in combination of two or more, if necessary. It is preferable to select in consideration of the reactivity with the functional group used in the coalescence.
Among these crosslinking agents, an isocyanate compound and an epoxy compound are preferred because the acrylic polymer can be easily crosslinked. Examples of the isocyanate compound include tolylene diisocyanate, xylylene diisocyanate, hexamethylene diisocyanate, and isophorone diisocyanate. Examples of the epoxy compound include ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, glycerin diglycidyl ether, neopentyl glycol diglycidyl ether, and 1,6-hexanediol diester. Glycidyl ether, tetraglycidyl xylenediamine, 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane, trimethylolpropane polyglycidyl ether, diglycerol polyglycidyl ether, polyglycerol polyglycidyl ether, sorbitol polyglycidyl ether, etc. Can be mentioned.

  In the first pressure-sensitive adhesive composition, the content of the crosslinking agent is appropriately selected according to the desired pressure-sensitive adhesive properties and the like, and is not particularly limited. For example, 0.01 parts by weight with respect to 100 parts by weight of the acrylic polymer The amount is preferably 5 parts by mass or less.

<Rubber polymer>
Examples of rubber polymers include styrene-isoprene-styrene block copolymer (SIS), styrene-butadiene-styrene block copolymer (SBS), hydrogenated styrene block copolymer, styrene-butadiene rubber (SBR). ), Polyisoprene rubber (IR), polyisobutylene (PIB), butyl rubber (IIR) and the like. These synthetic rubbers may be used alone or in combination of two or more.

Among these, the rubber-based polymer is preferably a styrene-based copolymer, more preferably a hydrogenated product of a styrene-based block copolymer, and further preferably a styrene-hydrogenated isoprene-styrene copolymer. preferable.
The weight average molecular weight (Mw) of the rubber polymer is preferably 10,000 or more and 1,000,000 or less, and more preferably 50,000 or more and 800,000 or less.

<Silicon polymer>
Examples of the silicon polymer include silicone rubbers such as polydimethylsiloxane and polymethylphenylsiloxane, silicone resins, and the like. These can be appropriately cross-linked by hydrogen abstraction from a methyl group by a peroxide, hydrosilylation using a cross-linking agent having a SiH group, an addition reaction with a platinum group catalyst compound, etc., and the adhesive properties can be adjusted.

(Other ingredients)
The 1st adhesive composition may contain other components other than the above in the range which does not impair the effect of this invention. As another component, a well-known component can be mentioned as an additive for adhesives. Examples thereof include light stabilizers such as antioxidants, metal corrosion inhibitors, tackifiers, silane coupling agents, hindered amine compounds, and the like.

  The first pressure-sensitive adhesive composition may contain a solvent. Examples of the solvent include methanol, ethanol, isopropanol, acetone, methyl ethyl ketone, toluene, n-hexane, n-butyl alcohol, methyl isobutyl ketone, methyl butyl ketone, ethyl butyl ketone, cyclohexanone, ethyl acetate, butyl acetate, propylene glycol monomethyl. Ether acetate, ethylene glycol monoethyl ether, propylene glycol monomethyl ether, N-methyl-2-pyrrolidone and the like are used. These may be used alone or in combination of two or more.

(Second adhesive layer)
The second pressure-sensitive adhesive layer is a layer provided on the first surface side of the base material layer. Here, the 1st surface of a base material layer is a surface in which the decoration layer was provided in part. The storage elastic modulus G ′ (1 Hz) at a measurement temperature of 25 ° C. and a frequency of 1 Hz of the second pressure-sensitive adhesive layer is 1 × 10 ⁴ Pa or more and 5 × 10 ⁵ Pa or less.

  The storage elastic modulus of the second pressure-sensitive adhesive layer is a value measured using Rheogel-E4000 manufactured by UBM Co., Ltd. The measurement temperature is 25 ° C., and the storage elastic modulus G ′ (1 Hz) at a frequency of 1 Hz is measured. In the measurement, the pressure-sensitive adhesive layer having a thickness of 150 μm or more and 250 μm or less is set to a strain of 1% and 2 ° C./Min.

  The thickness of the second pressure-sensitive adhesive layer is preferably adjusted as appropriate according to the thickness of the decorative layer provided on the base material layer. For example, when the thickness of the decorative layer is about 10 μm or more and 20 μm or less, the thickness of the second pressure-sensitive adhesive layer may be 50 μm or more, preferably 75 μm or more, and more preferably 100 μm or more. preferable. Further, the thickness of the second pressure-sensitive adhesive layer may be 500 μm or less, preferably 300 μm or less, and more preferably 200 μm or less. By setting the thickness of the second pressure-sensitive adhesive layer within the above range, in addition to the step formed by the decorative layer, it can easily follow the step of the adherend and suppress the generation of bubbles and the like. can do.

  Similarly to the first pressure-sensitive adhesive layer, the second pressure-sensitive adhesive layer is also preferably formed from a second pressure-sensitive adhesive composition containing a base polymer as a main component. The base polymer preferably contains at least one selected from an acrylic polymer, a rubber polymer, a silicon polymer, a urethane polymer, and a polyester polymer. Among them, the base polymer preferably includes at least one selected from an acrylic polymer, a rubber polymer, and a silicon polymer, and includes at least one selected from an acrylic polymer and a rubber polymer. It is more preferable that an acrylic polymer is included. That is, it is preferable that the second pressure-sensitive adhesive layer contains an acrylic polymer. Moreover, the 2nd adhesive layer may laminate | stack the adhesive layer containing an acrylic polymer, and the adhesive layer containing a rubber-type polymer.

The storage elastic modulus G ′ (1 Hz) at a measurement temperature of 25 ° C. and a frequency of 1 Hz of the second pressure-sensitive adhesive layer is 1 × 10 ⁴ Pa or more and 5 × 10 ⁵ Pa or less. The storage elastic modulus G ′ (1 Hz) of the second pressure-sensitive adhesive layer is within a predetermined range by adjusting the weight average molecular weight of the base polymer serving as the main agent, the glass transition temperature (Tg), the addition amount of the base polymer, and the like. Can be inside. By appropriately adjusting the weight average molecular weight, glass transition temperature (Tg), and addition amount of the base polymer, the crosslink density of the base polymer is adjusted, and the storage elastic modulus G ′ (1 Hz) may be within a desired range. preferable.

  Other components contained in the second pressure-sensitive adhesive composition are the same as other components contained in the first pressure-sensitive adhesive composition.

  The thickness of the second pressure-sensitive adhesive layer is preferably thicker than the thickness of the first pressure-sensitive adhesive layer. When the thickness of the first pressure-sensitive adhesive layer is A and the thickness of the second pressure-sensitive adhesive layer is B, B> A is preferable, B> 1.5A is more preferable, and B> More preferably, it is 2A. By setting the relationship between the thicknesses of the first pressure-sensitive adhesive layer and the second pressure-sensitive adhesive layer as described above, the outgas resistance and the step following property can be more effectively enhanced.

(Double-sided adhesive sheet with release sheet)
The present invention may relate to a double-sided pressure-sensitive adhesive sheet with a release sheet in which a release sheet is laminated on at least one surface of the above-mentioned double-sided pressure-sensitive adhesive sheet with a decorative layer (hereinafter also referred to as a double-sided pressure-sensitive adhesive sheet). The release sheet is laminated on at least one surface of the double-sided pressure-sensitive adhesive sheet, and is preferably laminated on both surfaces of the double-sided pressure-sensitive adhesive sheet.

  The release sheet is a sheet having releasability on at least one side. Examples of the release sheet include a peelable laminate sheet having a release sheet substrate and a release agent layer provided on one side of the release sheet substrate, and a polyolefin film such as a polyethylene film and a polypropylene film as a low polarity substrate. It is done.

Papers and polymer films are used as the release sheet substrate in the peelable laminate sheet. As the release agent constituting the release agent layer, for example, a general-purpose addition type or condensation type silicon release agent or a long-chain alkyl group-containing compound is used. In particular, an addition type silicon release agent having high reactivity is preferably used.
Specific examples of silicon release agents include BY24-4527 and SD-7220 manufactured by Toray Dow Corning Silicone, KS-3600, KS-774, and X62-2600 manufactured by Shin-Etsu Chemical Co., Ltd. Is mentioned. Further, the silicone release agent may contain a silicone resin which is an organosilicon compound having a SiO ₂ unit and a (CH ₃ ) ₃ SiO _1/2 unit or a CH ₂ ═CH (CH ₃ ) SiO _1/2 unit. preferable. Specific examples of the silicone resin include BY24-843, SD-7292, SHR-1404, etc. manufactured by Toray Dow Corning Silicone, KS-3800, X92-183, manufactured by Shin-Etsu Chemical Co., Ltd., and the like.

  In order for the release sheet to be easily peeled off, it is preferable that one release sheet and the other release sheet have different peelability. That is, when the peelability from one side and the peelability from the other are different, it becomes easy to peel only the release sheet having the higher peelability first. In that case, what is necessary is just to adjust the peelability of one peeling sheet and the other peeling sheet according to the bonding method and the bonding order.

(Manufacturing method of double-sided pressure-sensitive adhesive sheet with a decorative layer)
In the method for producing a double-sided pressure-sensitive adhesive sheet with a decorative layer of the present invention, the first pressure-sensitive adhesive composition is coated on the first release sheet to form a first pressure-sensitive adhesive layer having a thickness of 5 μm or more and 75 μm or less. A step of applying a second pressure-sensitive adhesive composition on the second release sheet to form a second pressure-sensitive adhesive layer, a first surface, and a first surface opposite to the first surface A step of partially forming a decorative layer on the first surface of the base material layer having two surfaces, a step of bonding the first pressure-sensitive adhesive layer to the second surface side of the base material layer, and a base material Bonding the second pressure-sensitive adhesive layer to the first surface side of the layer. Here, the storage elastic modulus G ′ (1 Hz) at a measurement temperature of 25 ° C. and a frequency of 1 Hz of the second pressure-sensitive adhesive layer is 1 × 10 ⁴ Pa or more and 5 × 10 ⁵ Pa or less.
Moreover, the manufacturing method of the double-sided adhesive sheet with a decorating layer of this invention has a decorating layer partially on the 1st surface of the base material layer which has a 1st surface and the 2nd surface on the opposite side to a 1st surface. Forming the first pressure-sensitive adhesive composition on the second surface side, forming a first pressure-sensitive adhesive layer having a thickness of 5 μm or more and 75 μm or less on the second surface side, The method may include a step of applying the second pressure-sensitive adhesive composition to form a second pressure-sensitive adhesive layer.

  In the step of partially forming the decorative layer on the first surface of the base material layer, a decorative printing layer can be formed by employing a printing method such as gravure printing or screen printing. In this case, examples of the paint for constituting the decorative print layer include ultraviolet curable ink and oxidation polymerization type ink.

  In the step of partially forming the decorative printed layer on the first surface of the base material layer, it is preferable that decorative printing for frame-shaped electrode concealment is performed. In the step of partially forming the decorative print layer on the first surface of the base material layer, a decorative print layer having a print pattern having design properties may be formed.

  In the step of forming the first pressure-sensitive adhesive layer, the first pressure-sensitive adhesive composition is applied on the first release sheet or on the second surface side of the base material layer. The first pressure-sensitive adhesive composition can be applied using a known coating apparatus. Examples of the coating apparatus include a blade coater, an air knife coater, a roll coater, a bar coater, a gravure coater, a micro gravure coater, a rod blade coater, a lip coater, a die coater, and a curtain coater. It is preferable to provide a heat drying step after coating, and it is preferable to use a known heating device such as a heating furnace or an infrared lamp in the heat drying step.

  In the step of forming the first pressure-sensitive adhesive layer, a first pressure-sensitive adhesive having a thickness of 5 μm to 75 μm is formed. In this case, the coating amount of the first pressure-sensitive adhesive composition can be appropriately determined according to the solid content concentration and viscosity of the pressure-sensitive adhesive composition.

  In the step of forming the second pressure-sensitive adhesive layer, the second pressure-sensitive adhesive composition is applied on the second release sheet or on the first surface side of the base material layer. When the second pressure-sensitive adhesive composition is applied to the first surface side of the base material layer, the second pressure-sensitive adhesive composition is placed on the exposed surface of the decorative layer and the first surface of the base material layer. Coated. In addition, the apparatus mentioned above can be mentioned similarly as a coating apparatus used at a coating process.

  In the step of forming the second pressure-sensitive adhesive layer, it is preferable to form a second pressure-sensitive adhesive layer having a thickness of 50 μm or more and 300 μm or less.

  The first pressure-sensitive adhesive layer and the second pressure-sensitive adhesive layer may be formed by applying each pressure-sensitive adhesive composition on each release sheet. In this case, the first pressure-sensitive adhesive layer and the second pressure-sensitive adhesive layer are formed on each release sheet. After the pressure-sensitive adhesive layer and the second pressure-sensitive adhesive layer are formed, they are bonded to each surface of the base material layer. When applying an adhesive composition on a peeling sheet, it can implement using a well-known coating apparatus. Examples of the coating apparatus include a blade coater, an air knife coater, a roll coater, a bar coater, a gravure coater, a micro gravure coater, a rod blade coater, a lip coater, a die coater, and a curtain coater. The coating film can be heated using a known heating device such as a heating furnace or an infrared lamp.

  When the second pressure-sensitive adhesive layer is a laminated pressure-sensitive adhesive layer, for example, two or more different types of pressure-sensitive adhesive layers may be laminated. In this case, the pressure-sensitive adhesive composition for forming the first pressure-sensitive adhesive layer is applied on the release sheet, while the pressure-sensitive adhesive composition for forming the second pressure-sensitive adhesive layer is applied on another release sheet. Then, the second pressure-sensitive adhesive layer having a laminated structure can be formed by pasting the two pressure-sensitive adhesive layers. Thus, the obtained 2nd adhesive layer is bonded by the 1st surface side of a base material layer after peeling at least one peeling sheet.

  A release sheet may be laminated on the exposed surfaces of the first pressure-sensitive adhesive layer and the second pressure-sensitive adhesive layer. In this case, after applying the first pressure-sensitive adhesive layer and the second pressure-sensitive adhesive layer on both surfaces of the substrate, a release sheet may be bonded onto each pressure-sensitive adhesive layer. Moreover, a 1st adhesive layer is applied on a peeling sheet, a 2nd adhesive layer is applied on another peeling sheet, and each adhesive layer is bonded to the predetermined surface of a base material layer. Thus, a double-sided pressure-sensitive adhesive sheet with a decorative layer on which a release sheet is laminated may be produced.

(Laminate)
The present invention provides a laminate comprising the above-mentioned double-sided pressure-sensitive adhesive sheet with a decorative layer, an adherend laminated on the first pressure-sensitive adhesive layer, and an adherend laminated on the second pressure-sensitive adhesive layer. It may be related to the body.

  FIG. 3 is a schematic cross-sectional view illustrating a configuration of a laminate formed by bonding an adherend using the double-sided pressure-sensitive adhesive sheet with a decorative layer of the present invention. As FIG. 3 shows, the laminated body 200 of this invention has the to-be-adhered body 30 and the to-be-adhered body 40 on both surfaces of the double-sided adhesive sheet 100 with a decoration layer, respectively.

  The adherend 30 is preferably a surface cover layer, and examples of the surface cover layer include a glass plate and a resin layer. Specific examples of the glass plate include those made of inorganic materials such as soda glass, non-alkali glass, and tempered glass. The surface cover layer is preferably a surface resin layer. In this case, the surface cover layer is made of a transparent resin such as polyethylene terephthalate resin (PET resin), polycarbonate resin (PC resin), polymethyl methacrylate resin (PMMA resin), or the like. A resin layer is preferably used. These surface resin layers may have a property of not transmitting ultraviolet rays.

  In addition, in this invention, since the base material layer has a decoration layer, the surface cover layer has the characteristics also in the point which does not have a printing layer. By adopting such a configuration, it becomes easy to cope with a reduction in thickness and an increase in size.

  The adherend 40 is preferably an optical member such as a display device. Examples of the display device include a liquid crystal display device (liquid crystal display panel), a plasma display device (plasma display panel), and an organic electroluminescence display device (organic EL panel).

  The features of the present invention will be described more specifically with reference to examples and comparative examples. The materials, amounts used, ratios, processing details, processing procedures, and the like shown in the following examples can be changed as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be construed as being limited by the specific examples shown below.

Example 1
Screen printing was performed on one surface (first surface) of a PET film (Toray Industries, Lumirror U483, thickness 50 μm) to form a frame-like decorative layer (frame printing). The thickness of the decoration layer was 20 μm.
Next, the first pressure-sensitive adhesive composition (manufactured by Shin-Tac Kasei Co., Ltd., SA151) was applied on the first release sheet with an applicator and dried at 100 ° C. for 2 minutes to form a first pressure-sensitive adhesive layer. After that, the PET film having a decorative layer was bonded to the surface (second surface) side where the decorative layer was not provided. Furthermore, the second pressure-sensitive adhesive composition (manufactured by New Tac Kasei Co., Ltd.) was put on another release sheet. , SA177) is coated with an applicator, dried at 100 ° C. for 2 minutes to form a second pressure-sensitive adhesive layer, and then a surface provided with a decorative layer of a PET film having a decorative layer (first surface) ). The thickness of each pressure-sensitive adhesive layer after drying was as shown in Table 1. Further, the storage elastic modulus G ′ (1 Hz) at 25 ° C. and a frequency of 1 Hz of the second pressure-sensitive adhesive layer was as shown in Table 1. Thus, the double-sided adhesive sheet with a decoration layer of Example 1 was obtained.

(Example 2)
A double-sided pressure-sensitive adhesive sheet with a decorative layer was prepared in the same manner as in Example 1 except that the coating amount of the pressure-sensitive adhesive composition was changed so that the thickness of the first pressure-sensitive adhesive layer was as shown in Table 1.

(Example 3)
Except for changing the coating amount of the pressure-sensitive adhesive composition so that the first pressure-sensitive adhesive composition is rubber A and the thickness of the first pressure-sensitive adhesive layer is as shown in Table 1, it is the same as in Example 1. Thus, a double-sided pressure-sensitive adhesive sheet with a decorative layer was produced.

<Rubber A>
Pellet styrene block copolymer (Kuraray Co., Ltd., product number: Septon 2063) 100 parts by mass, silane coupling agent (Shin-Etsu Chemical Co., Ltd., product number: X-41-1818) 0.6 parts by mass, styrene system 70 parts by mass of a tackifier (manufactured by Mitsui Chemicals, product number: FTR8100) and 50 parts by mass of paraffinic oil (product number: Diana Process Oil PW-90) were dissolved in toluene and stirred until uniform. An adhesive (rubber A) having a solid content concentration of 45% by mass was obtained. Stirring was performed at 23 ° C. for 4 hours. In addition, solid content refers to a rubber component, a silane coupling agent, a tackifier, and an oil component.

Example 4
A double-sided pressure-sensitive adhesive sheet with a decorative layer was prepared in the same manner as in Example 3 except that the coating amount of the pressure-sensitive adhesive composition was changed so that the thickness of the first pressure-sensitive adhesive layer was as shown in Table 1.

(Example 5)
Except for changing the coating amount of the pressure-sensitive adhesive composition so that the first pressure-sensitive adhesive composition is silicon A and the thickness of the first pressure-sensitive adhesive layer is as shown in Table 1, it is the same as in Example 1. Thus, a double-sided pressure-sensitive adhesive sheet with a decorative layer was produced.

<Silicon A>
0.5 parts by mass of platinum catalyst (CAT-PL-50T manufactured by Shin-Etsu Chemical Co., Ltd.) is added to 100 parts by mass of KR3700 manufactured by Shin-Etsu Chemical Co., Ltd. and stirred until uniform to obtain an adhesive (silicone A). It was.

(Example 6)
A double-sided pressure-sensitive adhesive sheet with a decorative layer was produced in the same manner as in Example 5 except that the coating amount of the pressure-sensitive adhesive composition was changed so that the thickness of the first pressure-sensitive adhesive layer was as shown in Table 1.

(Example 7)
The coating amount of the pressure-sensitive adhesive composition was changed so that the thickness of the first pressure-sensitive adhesive layer was as shown in Table 1, and the second pressure-sensitive adhesive composition was changed to NA017 manufactured by New Tack Kasei Co., Ltd. Except for this, a double-sided PSA sheet with a decorative layer was produced in the same manner as in Example 1. The storage elastic modulus G ′ (1 Hz) at 25 ° C. and a frequency of 1 Hz of the second pressure-sensitive adhesive layer was as shown in Table 1.

(Example 8)
A double-sided pressure-sensitive adhesive sheet with a decorative layer was produced in the same manner as in Example 7 except that the second pressure-sensitive adhesive composition was changed to EA147 manufactured by New Tack Kasei Co., Ltd. The storage elastic modulus G ′ (1 Hz) at 25 ° C. and a frequency of 1 Hz of the second pressure-sensitive adhesive layer was as shown in Table 1.

Example 9
The second pressure-sensitive adhesive layer was a rubber / acrylic laminate, and the thickness of the second pressure-sensitive adhesive layer was changed as shown in Table 1. Then, the 2nd adhesive layer was bonded to the surface (1st surface) in which the decorating layer of PET film which has a decorating layer was provided. Others were carried out similarly to Example 7, and produced the double-sided adhesive sheet with a decoration layer. The storage elastic modulus G ′ (1 Hz) at 25 ° C. and a frequency of 1 Hz of the second pressure-sensitive adhesive layer was as shown in Table 1.

<Rubber / Acrylic>
The rubber layer of the rubber acrylic laminate is a pressure-sensitive adhesive layer having a thickness of 225 μm composed of rubber A used in Example 3, and the acrylic layer is a pressure-sensitive adhesive layer having a thickness of 25 μm composed of SA031 manufactured by Shin-Tac Kasei. is there. Each adhesive layer was laminated | stacked and it was set as the 2nd adhesive layer.

(Comparative Example 1)
A double-sided pressure-sensitive adhesive sheet with a decorative layer was prepared in the same manner as in Example 1 except that the coating amount of the pressure-sensitive adhesive composition was changed so that the thickness of the first pressure-sensitive adhesive layer was as shown in Table 1.

(Comparative Example 2)
A double-sided PSA sheet with a decorative layer was produced in the same manner as in Example 7 except that the second PSA composition was changed to Rubber A. The storage elastic modulus G ′ (1 Hz) at 25 ° C. and a frequency of 1 Hz of the second pressure-sensitive adhesive layer was as shown in Table 1.

(Evaluation)
(Storage modulus G ')
The storage elastic modulus G ′ of the second pressure-sensitive adhesive layer was measured using Rheogel-E4000 manufactured by UBM Co., Ltd. The measurement temperature was 25 ° C., and the storage elastic modulus G ′ (1 Hz) at a frequency of 1 Hz was measured. In the measurement, the pressure-sensitive adhesive layer having a thickness of 150 μm or more and 250 μm or less was set to a strain of 1% and 2 ° C./Min.

(Foam resistance (outgas resistance))
The double-sided pressure-sensitive adhesive sheet with a decorative layer obtained in Examples and Comparative Examples was cut into a size of 55 mm × 80 mm, and on the first pressure-sensitive adhesive layer side, PC (polycarbonate resin) and PMMA (polyethylene resin) manufactured by Mitsubishi Gas Chemical Company, Inc. were used. The double-sided pressure-sensitive adhesive sheet with a decorative layer and the PC / PMMA co-extruded film were bonded so that the PC side of the co-extruded film (methyl methacrylate resin) (trade name: MR58) came. Furthermore, the glass plate was bonded to the 2nd adhesive layer side of the double-sided adhesive sheet with a decoration layer, and the autoclave defoaming process was performed on the conditions of 40 degreeC, 0.5 MPa, and 30 minutes. Then, a PC / PMMA coextruded film, a double-sided pressure-sensitive adhesive sheet with a decorative layer, and a laminate of glass plates were placed in an environment of 85 ° C. and a relative humidity of 0 to 24% for 24 hours. The laminate was observed from the side of the coextruded film of PC / PMMA, and the presence or absence of bubbles was evaluated according to the following evaluation criteria.
◯: There are no air bubbles in the central part of the laminate (area 10 mm or more away from the edge of the decorative layer).
(Triangle | delta): Although there exists a bubble in the center part of a laminated body, it is a bubble with a diameter of less than 200 micrometers.
X: There is a large bubble having a diameter of 200 μm or more at the center of the laminate.

(Step following capability)
A PC / PMMA co-extruded film, a double-sided pressure-sensitive adhesive sheet with a decorative layer, and a laminated body of glass plates are prepared in the same manner as the foaming resistance evaluation method. After the endurance test, the laminate was observed from the PC / PMMA coextruded film surface side, and the generation of bubbles around the frame printing (including the decoration layer and the area less than 10 mm away from the edge of the decoration layer) The following evaluation criteria evaluated the presence or absence (step followability).
○: No bubbles around the frame printing.
Δ: Bubbles are generated at the corners of the frame printing, but there are no bubbles around the long side and the short side.
X: There are bubbles around both corners and sides of the frame printing.

  It turns out that the double-sided adhesive sheet with a decoration layer obtained in the Example is excellent in outgas resistance and level | step difference followability. On the other hand, the double-sided pressure-sensitive adhesive sheet with a decorative layer obtained in the comparative example was not compatible with outgas resistance and step following ability.

  The laminated body was also producible using the double-sided adhesive sheet with a decoration layer obtained in the Example. The release sheet on the first pressure-sensitive adhesive layer side of the double-sided pressure-sensitive adhesive sheet with a decorative layer was peeled off and bonded to the resin cover, and then the release sheet on the second pressure-sensitive adhesive layer side was peeled off and roll-bonded to the display device.

DESCRIPTION OF SYMBOLS 5 Decorating layer 10 Base material layer 10a Base material resin layer 10b Functional layer 12 1st adhesive layer 14 2nd adhesive layer 30 Adhering body 40 Adhering body 100 Double-sided adhesive sheet 200 with a decorating layer Laminated body

Claims (8)

A base material layer having a first surface and a second surface opposite to the first surface, the base material layer having a decorative layer on a part of the first surface;
Having a first pressure-sensitive adhesive layer having a thickness of 5 μm or more and 75 μm or less on the second surface side;
A second pressure-sensitive adhesive layer on the first surface side;
A double-sided pressure-sensitive adhesive sheet with a decorative layer, wherein the storage pressure modulus G ′ (1 Hz) at a measurement temperature of 25 ° C. and a frequency of 1 Hz of the second pressure-sensitive adhesive layer is 1 × 10 ⁴ Pa or more and 5 × 10 ⁵ Pa or less.   The double-sided pressure-sensitive adhesive sheet with a decorative layer according to claim 1, wherein the base material layer has a multilayer structure.   The said base material layer is a double-sided adhesive sheet with a decorating layer of Claim 1 or 2 containing a base material resin layer and at least 1 layer selected from a primer layer and a hard-coat layer.   The double-sided pressure-sensitive adhesive sheet with a decorative layer according to any one of claims 1 to 3, wherein the first pressure-sensitive adhesive layer contains an acrylic polymer.   The double-sided pressure-sensitive adhesive sheet with a decorative layer according to any one of claims 1 to 4, wherein the second pressure-sensitive adhesive layer contains an acrylic polymer.   The double-sided pressure-sensitive adhesive sheet with a decorative layer according to any one of claims 1 to 5, wherein the first pressure-sensitive adhesive layer is bonded to a surface resin layer.   The double-sided pressure-sensitive adhesive sheet with a decorative layer according to any one of claims 1 to 6, wherein the second pressure-sensitive adhesive layer is bonded to a display device.   A double-sided pressure-sensitive adhesive sheet with a decorative layer according to any one of claims 1 to 7, a surface resin layer laminated on the first pressure-sensitive adhesive layer, and a layer laminated on the second pressure-sensitive adhesive layer. And a laminated body comprising the display device.

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