CN112703238A - Adhesive sheet for bonding transparent member, method for producing laminate, and laminate - Google Patents

Abstract

The present invention aims to provide a pressure-sensitive adhesive sheet that can improve the design of a display showing a black screen when the pressure-sensitive adhesive sheet is bonded to the display. The present invention relates to a pressure-sensitive adhesive sheet for bonding optical components, comprising an acrylic polymer and a colorant, wherein the colorant comprises at least one selected from metal oxides and carbon black.

Description

Adhesive sheet for bonding transparent member, method for producing laminate, and laminate

Technical Field

The present invention relates to an adhesive sheet for bonding a transparent member, a method for producing a laminate, and a laminate.

Background

Conventionally, input devices used in combination with display devices such as Liquid Crystal Displays (LCDs) or display devices such as touch panels have been widely used. For manufacturing these display devices and input devices, transparent adhesive sheets are used for applications of bonding optical members.

For example, patent document 1 discloses a double-sided adhesive sheet including a laminate including a flexible base layer, first and second black layers, and first and second adhesive layers. In such a case, the pressure-sensitive adhesive sheet for attaching the black layer is sometimes required to have design properties such that the black appearance is not impaired.

However, as a means for imparting a black appearance to an adhesive sheet, a method of adding a pigment to an adhesive sheet is also known. For example, patent document 2 discloses a black foil-like adhesive containing an adhesive component, a black pigment, and a styrene-maleic acid resin.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2005-060435

Patent document 2: japanese patent laid-open publication No. 2013-32430

Disclosure of Invention

As described above, a black pressure-sensitive adhesive sheet obtained by coloring a substrate or a pressure-sensitive adhesive is known, but such a pressure-sensitive adhesive sheet does not consider bonding to a transparent member or a display surface, and design and the like when bonding a display surface to a pressure-sensitive adhesive sheet are not studied.

In order to solve the above-described conventional problems, the present inventors have studied for the purpose of providing an adhesive sheet which can improve the design properties when the adhesive sheet is attached to a display or the like on which a black screen is displayed.

The present inventors have also studied for the purpose of providing a laminate in which a display surface and an ITO-containing layer are bonded to a colorant-containing pressure-sensitive adhesive layer, and which exhibits excellent design properties.

As a result of intensive studies to solve the above problems, the present inventors have found that: by blending a colorant with an acrylic polymer-containing pressure-sensitive adhesive sheet, a pressure-sensitive adhesive sheet is obtained which is improved in design properties when the pressure-sensitive adhesive sheet is attached to a display or the like which displays a black screen.

Specifically, the present invention has the following configuration.

[1] An adhesive sheet for bonding a transparent member, comprising an acrylic polymer and a colorant.

[2] The pressure-sensitive adhesive sheet for bonding a transparent member according to [1], wherein the product of the total light transmittance and the haze value is 170 or less.

[3] The pressure-sensitive adhesive sheet for bonding a transparent member according to [1] or [2], wherein the colorant contains at least 1 selected from the group consisting of metal oxides and carbon black.

[4] The adhesive sheet for sticking a transparent member according to any one of [1] to [3], wherein the colorant is a metal oxide.

[5] The pressure-sensitive adhesive sheet for sticking a transparent member according to any one of [1] to [4], wherein the acid value of the acrylic polymer is 50mgKOH/g or less.

[6] The adhesive sheet for bonding a transparent member according to any one of [1] to [5], wherein the total light transmittance is 5 to 90%.

[7] The adhesive sheet for sticking a transparent member according to any one of [1] to [6], wherein the haze is 0.1 to 15%.

[8] The pressure-sensitive adhesive sheet for sticking a transparent member according to any one of [1] to [7], wherein the colorant has a primary average particle diameter of 0.01 to 15 μm.

[9] The adhesive sheet for bonding a transparent member according to any one of [1] to [8], wherein the adhesive sheet for bonding a transparent member further contains an ultraviolet absorber.

[10] The pressure-sensitive adhesive sheet for sticking a transparent member according to [9], wherein the ultraviolet absorber is represented by the following general formula (1) or (2),

[ solution 1]

General formula (1)

In the general formula (1), R¹Represents a hydrogen atom, a halogen atom, an alkoxy group having 1 to 4 carbon atoms, a nitro group or a cyano group, R²R represents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms³Represents a structural system of an alkyl group system,

[ solution 2]

General formula (2)

In the general formula (2), R⁴、R⁵And R⁶Is a hydrogen atom, a hydroxyl group, an alkyl system structure or a halogen atom, and R⁴、R⁵And R⁶Not all hydrogen atoms.

[11] The adhesive sheet for bonding a transparent member according to any one of [1] to [8], further comprising a photopolymerization initiator and an acrylic monomer, and being in a semi-cured state.

[12] The adhesive sheet for sticking a transparent member according to any one of [1] to [11], wherein the thickness is 1 to 5000 μm.

[13] The adhesive sheet for sticking a transparent member according to any one of [1] to [12], wherein the transparent member is an optical member.

[14] A method for producing a laminate, comprising the step of bonding the adhesive sheet according to [11] to an adherend in a semi-cured state, and then irradiating the adhesive sheet with active energy rays to post-cure the adhesive sheet.

[15] A laminate comprising a surface layer, an adhesive layer and a layer comprising a conductive member in this order, wherein the adhesive layer comprises an acrylic polymer and a colorant.

[16] The laminate according to [15], wherein the surface layer is a glass layer or a resin layer.

[17] The laminate according to [15] or [17], wherein the layer containing the conductive member is a touch sensor.

[18] The laminate according to any one of [15] to [17], wherein the colorant is a black colorant.

[19] The laminate according to any one of [15] to [18], wherein the colorant is a black pigment.

[20] The laminate according to any one of [15] to [19], wherein the colorant contains at least 1 selected from a metal oxide and carbon black.

[21] The laminate according to any one of [15] to [20], wherein the total light transmittance of the adhesive layer is 5 to 90%.

[22] The laminate according to any one of [15] to [21], wherein the adhesive layer has a haze of 0.1 to 15%.

[23] The laminate according to any one of [15] to [22], wherein the colorant is a black pigment, and the black pigment has a primary average particle diameter of 0.01 μm or more and less than 5 μm.

(effect of the invention)

According to the present invention, a pressure-sensitive adhesive sheet for bonding a transparent member, which can improve the design when the pressure-sensitive adhesive sheet is bonded to a display or the like that displays a black screen, can be obtained. In addition, according to the present invention, a laminate exhibiting excellent design properties can be obtained.

Drawings

Fig. 1 is a schematic view showing a cross section of a pressure-sensitive adhesive sheet having a release sheet.

Fig. 2 is a sectional view illustrating the structure of the laminated body.

Detailed Description

The present invention will be described in detail below. The following description of the constituent elements may be based on a representative embodiment and a specific example, but the present invention is not limited to such an embodiment. In the present specification, the numerical range expressed by the term "to" means a range including numerical values before and after the term "to" as a lower limit value and an upper limit value.

(adhesive sheet)

The present invention relates to an adhesive sheet for use in bonding a transparent member. The adhesive sheet of the present invention comprises an acrylic polymer and a colorant. The pressure-sensitive adhesive sheet of the present invention is used for bonding a transparent member, but the transparent member is preferably an optical member. That is, the adhesive sheet for bonding a transparent member of the present invention is preferably an adhesive sheet for bonding an optical member.

The pressure-sensitive adhesive sheet for bonding a transparent member (hereinafter, also referred to as a pressure-sensitive adhesive sheet) of the present invention is a pressure-sensitive adhesive sheet having the above-described structure, and therefore, when the pressure-sensitive adhesive sheet is bonded to a display or the like on which a black screen is displayed, the design properties can be improved. Specifically, when the adhesive sheet of the present invention is bonded to a display that displays a black screen, the degree of black coloration of the display (the degree of preference of black chromaticity) can be increased, and thus the design of the display and a display device having the display can be improved. In addition, even in a display in which a black screen is not displayed, since the black chromaticity of the display is improved by attaching the adhesive sheet, the sense of unity with the surroundings is emphasized, and the design is improved.

The pressure-sensitive adhesive sheet for bonding a transparent member of the present invention has high visibility, and can prevent blurring or blurring of characters displayed on a display even when the pressure-sensitive adhesive sheet is bonded to a viewing surface side of the display, for example. Thus, the pressure-sensitive adhesive sheet for bonding a transparent member of the present invention successfully improves the degree of black coloration of a display or the like without reducing the visibility of the display or the like.

The total light transmittance of the psa sheet is preferably 5% or more, more preferably 10% or more, even more preferably 20% or more, even more preferably 30% or more, and particularly preferably 40% or more. The total light transmittance of the psa sheet is preferably 90% or less, more preferably 86% or less, even more preferably 80% or less, even more preferably 75% or less, even more preferably 70% or less, and particularly preferably 65% or less. By setting the total light transmittance of the pressure-sensitive adhesive sheet within the above range, the degree of black color development of a display or the like can be more effectively improved.

The lower limit of the haze of the pressure-sensitive adhesive sheet is not particularly limited, but is preferably 0.1% or more, and more preferably 0.5% or more. The haze of the pressure-sensitive adhesive sheet is preferably 30% or less, more preferably 25% or less, further preferably 20% or less, further preferably 15% or less, further preferably 10% or less, further preferably 8% or less, and particularly preferably 6% or less. When the haze of the pressure-sensitive adhesive sheet is within the above range, the degree of black color development of a display or the like can be increased, and visibility can be maintained.

In the psa sheet of the present invention, the product of the total light transmittance and the haze value of the psa sheet is preferably 170 or less, more preferably 165 or less, even more preferably 160 or less, even more preferably 155 or less, and particularly preferably 150 or less. The product of the total light transmittance and the haze value of the pressure-sensitive adhesive sheet is preferably 10 or more, more preferably 30 or more. Among them, the total light transmittance of the pressure-sensitive adhesive sheet is preferably 40% or more and the haze is preferably 6% or less, and the total light transmittance of the pressure-sensitive adhesive sheet is preferably 90% or less and the haze is preferably 0.1% or more. When the product of the total light transmittance and the haze value is in the above range and the total light transmittance and the haze of the pressure-sensitive adhesive sheet are in the predetermined ranges, the degree of black color development of a display or the like can be more effectively improved and the visibility of the display or the like can be more effectively improved.

The thickness of the pressure-sensitive adhesive sheet is preferably 1 μm or more, more preferably 10 μm or more, still more preferably 20 μm or more, and still more preferably 50 μm or more. The thickness of the pressure-sensitive adhesive sheet is preferably 5000 μm or less, more preferably 3000 μm or less, and still more preferably 1000 μm or less. By setting the thickness of the pressure-sensitive adhesive sheet to the upper limit or less, it is possible to prevent water vapor from entering from the edge and improve durability. On the other hand, by setting the thickness of the adhesive sheet to be equal to or more than the lower limit value, handling of the adhesive sheet can be facilitated.

The adhesive sheet of the present invention may be a single-layer adhesive sheet. The pressure-sensitive adhesive sheet may be a single-sided pressure-sensitive adhesive sheet having a substrate (preferably a transparent substrate) on one side, or may be a double-sided pressure-sensitive adhesive sheet. Examples of double-sided pressure-sensitive adhesive sheets include: a single-layer adhesive sheet comprising an adhesive layer, a multilayer adhesive sheet having a plurality of adhesive layers laminated thereon, a multilayer adhesive sheet having another adhesive layer laminated between an adhesive layer and an adhesive layer, a multilayer adhesive sheet having a support laminated between an adhesive layer and an adhesive layer, and a multilayer adhesive sheet having an adhesive layer laminated on one surface of a support and another adhesive layer laminated on the other surface. In the case where the double-sided adhesive sheet has a support, a double-sided adhesive sheet using a transparent support as the support is preferable. As the support, a general film used in the optical field like the transparent substrate can be used. Such a double-sided pressure-sensitive adhesive sheet is excellent in transparency as a whole, and therefore can be suitably used for bonding between transparent members or optical members.

As shown in fig. 1, the present invention may be a release-sheet-attached pressure-sensitive adhesive sheet including a release sheet 12a and a release sheet 12b on both surfaces of a pressure-sensitive adhesive sheet 11. Examples of the release sheet include a releasable laminate sheet having a release sheet substrate and a release agent layer provided on one surface of the release sheet substrate, and polyolefin films such as polyethylene films and polypropylene films as low-polarity substrates.

Paper or a polymer film can be used as the release sheet substrate in the releasable laminate sheet. In optical applications, a polymer film is preferably used to prevent the incorporation of foreign substances. Examples of the release agent constituting the release agent layer include general-purpose addition or condensation type silicone release agents and long chain alkyl group-containing compounds. In particular, an addition silicone release agent having high reactivity is preferably used.

Specific examples of the silicone release agent include: BY24-4527 and SD-7220 available from Toray Dow Corning Silicone oil (Toray Dow Corning Silicone); KS-3600, KS-774, X62-2600, and the like, available from shin Etsu chemical industries, Ltd. Preferably, the silicone-based release agent contains a silicone resin having SiO₂Unit and (CH)₃)₃SiO_1/2Unit or CH₂＝CH(CH₃)SiO_1/2A unit of an organosilicon compound. Specific examples of the silicone resin include: BY24-843, SD-7292, and SHR-1404 manufactured BY Toray Dow Corning Silicone oil (Toray Dow Corning Silicone); KS-3800 and X92-183, manufactured by shin-Etsu chemical industries, Ltd.

As the releasable laminate sheet, a commercially available product can be used. Examples thereof include: a heavy separator made by Teijin Dupont Film co.ltd. as a polyethylene terephthalate Film subjected to mold release treatment, and a light separator made by Teijin Dupont Film co.ltd. as a polyethylene terephthalate Film subjected to mold release treatment.

When the pressure-sensitive adhesive sheet of the present invention is a double-sided pressure-sensitive adhesive sheet, it is preferable to have a pair of release sheets having mutually different release forces. That is, in the release sheet, in order to facilitate the release, it is preferable that the releasability is different between one release sheet and the other release sheet. When the peelability from one side is different from that from the other side, it is easy to peel only the one having the high peelability first.

The gel fraction of the pressure-sensitive adhesive sheet of the present invention is preferably 30% by mass or more, more preferably 40% by mass or more, even more preferably 50% by mass or more, even more preferably 60% by mass or more, and even more preferably 65% by mass or more. The gel fraction of the pressure-sensitive adhesive sheet is preferably 100% by mass or less, and more preferably 99% by mass or less. By setting the gel fraction within the above range, durability and adhesive force can be both satisfied.

The gel fraction of the adhesive sheet is a value measured by the following method. First, about 0.1g of the adhesive sheet was collected in a sample bottle, 30ml of ethyl acetate was added thereto, and the mixture was shaken for 24 hours. Thereafter, the content of the sample bottle was separated by filtration through a 150-mesh stainless steel wire mesh, and the residue on the wire mesh was dried at 100 ℃ for 1 hour to measure the dry mass (g). From the obtained dry mass, the gel fraction was calculated according to the following formula 1.

Gel fraction (%) (dry mass/collected mass of adhesive sheet) × 100 · formula 1

The adhesive sheet of the present invention is a semi-cured adhesive sheet, and may be an adhesive sheet having post-curing properties. In this case, the adhesive sheet preferably further contains a photopolymerization initiator and an acrylic monomer.

Here, in the present specification, when the gel fraction of the adhesive sheet is increased by 10 mass% or more by irradiating with an active energy ray or heating under the following conditions, the adhesive sheet before irradiation or heating is in a semi-cured state. At this time, when the adhesive sheet is post-cured by irradiation with active energy rays, an optically transparent PET separator is bonded to both surfaces of the adhesive sheet, and the cumulative light amount is adjusted to 3000mJ/cm from the optically transparent PET separator side²The method of (1) irradiating active energy rays (high-pressure mercury lamp or metal halide lamp). In addition, in the case of post-curing the adhesive sheet by heating, the heat treatment was performed in an oven at 100 ℃ for 3 hours in a state where the release films were bonded to both surfaces of the adhesive sheet.

In the case where the pressure-sensitive adhesive sheet is a semi-cured pressure-sensitive adhesive sheet, the gel fraction of the pressure-sensitive adhesive sheet is preferably 10% by mass or more, more preferably 15% by mass or more, and still more preferably 20% by mass or more. In addition, in the case where the adhesive sheet is a semi-cured adhesive sheet, the gel fraction of the adhesive sheet is preferably less than 70% by mass.

When the adhesive sheet of the present invention is a semi-cured adhesive sheet and has post-curing properties, the gel fraction of the adhesive sheet after post-curing is preferably 70 mass% or more.

The pressure-sensitive adhesive sheet of the present invention is also excellent in durability and processability, and when the pressure-sensitive adhesive sheet is a semi-cured pressure-sensitive adhesive sheet and is post-cured after being bonded to an adherend, the pressure-sensitive adhesive sheet can exhibit more excellent durability and processability. The pressure-sensitive adhesive sheet after post-curing improves the cohesive force of the pressure-sensitive adhesive and firmly adheres to an adherend, and therefore, even when left in a high-temperature environment for a long period of time, does not peel from the adherend or float from the adherend. Such a pressure-sensitive adhesive sheet can be said to have excellent durability. In addition, in the pressure-sensitive adhesive sheet after post-curing, since the end face can be suppressed from being sticky, for example, adhesion of the pressure-sensitive adhesive to a press blade during press processing, deformation of the pressure-sensitive adhesive sheet caused by the adhesion, and the like can be prevented. Further, when the adhesive sheet after post-curing is press-worked into a desired size and then subjected to removal processing for the purpose of adjusting the end face, deformation, overflow, peeling, and the like of the adhesive sheet do not occur. Thus, the pressure-sensitive adhesive sheet of the present invention can exhibit excellent processability.

(acrylic acid Polymer)

The acrylic polymer is not particularly limited as long as it is an acrylic polymer having an acrylic monomer unit, and for example, an acrylic polymer containing a non-crosslinkable (meth) acrylate unit (a1) and an acrylic monomer unit (a2) having a crosslinkable functional group is preferable. In the present specification and claims, "unit" is a repeating unit (monomer unit) constituting a polymer.

The non-crosslinkable (meth) acrylate unit (a1) is a repeating unit derived from an alkyl (meth) acrylate. Examples of the alkyl (meth) acrylate include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, t-butyl (meth) acrylate, n-pentyl (meth) acrylate, n-hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, isooctyl (meth) acrylate, n-nonyl (meth) acrylate, isononyl (meth) acrylate, n-decyl (meth) acrylate, isodecyl (meth) acrylate, n-undecyl (meth) acrylate, n-dodecyl (meth) acrylate, stearyl (meth) acrylate, methoxyethyl (meth) acrylate, ethoxyethyl (meth) acrylate, and the like, Cyclohexyl (meth) acrylate, benzyl (meth) acrylate, and the like. These may be used alone in1 kind, or may be used in combination of 2 or more kinds.

Among the above-mentioned alkyl (meth) acrylates, at least 1 selected from the group consisting of methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate and 2-ethylhexyl (meth) acrylate is preferable from the viewpoint of improving the adhesiveness.

The acrylic monomer unit (a2) having a crosslinkable functional group is preferably at least one selected from a carboxyl group-containing monomer unit, a hydroxyl group-containing monomer unit, an amino group-containing monomer unit, and a glycidyl group-containing monomer unit. That is, the acrylic polymer preferably has at least one crosslinkable functional group selected from a carboxyl group, a hydroxyl group, an amino group, an amide group, a glycidyl group and an isocyanate group.

Examples of the monomer unit having a carboxyl group include acrylic acid and methacrylic acid.

The hydroxyl group-containing monomer unit is a repeating unit derived from a hydroxyl group-containing monomer. Examples of the hydroxyl group-containing monomer include: hydroxyalkyl (meth) acrylates such as 2-hydroxyethyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, and 2-hydroxypropyl (meth) acrylate; (meth) acrylic acid lactones such as (meth) acrylic acid mono (diethylene glycol), (meth) acrylic acid [ (mono-, di-or poly-) alkylene glycol ], and (meth) acrylic acid monocaprolactone.

Examples of the amino group-containing monomer unit include repeating units derived from amino group-containing monomers such as (meth) acrylamide and allylamine.

Examples of the glycidyl group-containing monomer unit include a repeating unit derived from a glycidyl group-containing monomer such as glycidyl (meth) acrylate.

The content of the acrylic monomer unit (a2) having a crosslinkable functional group in the acrylic polymer is preferably 0.01 to 40% by mass, and more preferably 0.5 to 35% by mass. By setting the content of the acrylic monomer unit (a2) having a crosslinkable functional group to be within the above range, the crosslinkability and adhesiveness of the acrylic polymer can be easily controlled.

The acrylic polymer may further comprise units derived from (meth) acrylates containing alkoxyalkyl groups. The alkoxyalkyl group-containing (meth) acrylate is an alkoxyalkyl (meth) acrylate. The alkoxyalkyl (meth) acrylate is preferably, for example, an alkoxyalkyl (meth) acrylate in which the alkoxy group has 1 to 12 carbon atoms and the alkylene group bonded to the alkoxy group has 1 to 18 carbon atoms. The alkoxy group preferably has 1 to 8 carbon atoms, more preferably 1 to 4 carbon atoms, and particularly preferably 1 or 2 carbon atoms. The number of carbon atoms of the alkylene group bonded to the alkoxy group is preferably 1 to 12, more preferably 1 to 8, further preferably 1 to 4, and particularly preferably 1 to 3.

Examples of such alkoxyalkyl (meth) acrylates include 2-methoxymethyl (meth) acrylate, 2-methoxyethyl (meth) acrylate, 2-ethoxymethyl (meth) acrylate, 2-ethoxyethyl (meth) acrylate, 3-methoxypropyl (meth) acrylate, 3-ethoxypropyl (meth) acrylate, 4-methoxybutyl (meth) acrylate, and 4-ethoxybutyl (meth) acrylate.

The acrylic polymer may further comprise units derived from a nitrogen-containing monomer. The nitrogen-containing monomer is a monomer containing nitrogen in1 molecule. Examples of the nitrogen-containing monomer include dimethylacrylamide, diethylacrylamide, acryloylmorpholine, hydroxyethylacrylamide, hydroxymethylacrylamide, methoxymethylacrylamide, ethoxymethylacrylamide, dimethylaminoethylacrylamide, N-vinylcaprolactam, N-vinyl-2-pyrrolidone, dimethylaminoethyl (meth) acrylate, and N-vinylformamide. Among them, the nitrogen-containing monomer is preferably at least 1 selected from the group consisting of an acrylamide derivative, an amino group-containing monomer and a nitrogen-containing heterocycle-containing monomer, and more preferably an acrylamide derivative. The acrylamide derivative is more preferably at least 1 selected from the group consisting of dimethylacrylamide, diethylacrylamide and acryloylmorpholine, and particularly preferably dimethylacrylamide or diethylacrylamide.

The acrylic polymer may have other monomer units as necessary. The other monomer may be any monomer copolymerizable with the above-mentioned acrylic monomer, and examples thereof include (meth) acrylonitrile, vinyl acetate, styrene, vinyl chloride, vinyl pyrrolidone, and vinyl pyridine. The content of the other monomer unit in the acrylic polymer is preferably 20% by mass or less, and more preferably 15% by mass or less.

The acid value of the acrylic polymer is preferably 50mgKOH/g or less, more preferably 40mgKOH/g or less, still more preferably 30mgKOH/g or less, yet more preferably 20mgKOH/g or less, yet more preferably 10mgKOH/g or less, and particularly preferably 5mgKOH/g or less. Further, the acid value of the acrylic polymer may be 0 mgKOH/g. When the acid value of the acrylic polymer is in the above range, the adhesive sheet of the present invention has excellent discoloration resistance. Specifically, by setting the acid value of the acrylic polymer within the above range, the increase in total light transmittance can be suppressed even when the adhesive sheet is left under high-temperature and high-humidity conditions for a long period of time. The total light transmittance of the adhesive sheet before and after being left to stand in an environment of 85 ℃ and 85% relative humidity for 240 hours is measured, and the amount of change in the total light transmittance calculated from the value is preferably less than 10%. Further, the total light transmittance of the pressure-sensitive adhesive sheet after being left for 240 hours at 85 ℃ under an atmosphere of 85% relative humidity is preferably less than 85%. Further, the amount of change in the total light transmittance is calculated by the following equation.

Change (%) - (total light transmittance of sample before treatment) - (total light transmittance of sample after treatment)

The acid value of the acrylic polymer was measured in accordance with JIS K0070 (1992). Specifically, about 2g of a sample was precisely weighed in a 100ml Erlenmeyer flask using a precision balance, and 10ml of a mixed solvent of ethanol/diethyl ether (weight ratio) 1/1 was added thereto and dissolved. And dripping 1-3 drops of phenolphthalein ethanol solution serving as an indicator into the container, and fully stirring until the sample becomes uniform. This was titrated with a 0.1N potassium hydroxide-ethanol solution, and a point of time at which the light red color of the indicator lasted for 30 seconds was taken as the end point of neutralization. From the results, the value obtained by using the following calculation formula (1) was used as the acid value of the sample.

Acid value (mgKOH/g) ([ B × f × 5.611]/S (1)

In the formula (1), B is the amount (ml) of the 0.1N potassium hydroxide-ethanol solution used, f is a factor of the 0.1N potassium hydroxide-ethanol solution, and S is the amount (g) of the sample collected.

The weight average molecular weight of the acrylic polymer is preferably 10 to 200 ten thousand, more preferably 20 to 150 ten thousand. The weight average molecular weight of the acrylic polymer is a value before crosslinking by a crosslinking agent described later. The weight average molecular weight is a value measured by Size Exclusion Chromatography (SEC) and determined on a polystyrene basis. As the acrylic polymer, commercially available products may be used, or those synthesized by a known method may be used.

(coloring agent)

The adhesive sheet of the present invention contains a colorant. Examples of the colorant include a dye colorant and a pigment colorant. Among them, the colorant is preferably a pigment colorant, more preferably a black colorant, and more preferably at least 1 selected from the group consisting of metal oxides and carbon black. The colorant is more preferably a black pigment, and particularly preferably a metal oxide. By using a metal oxide as a colorant, the visibility of the adhesive sheet can be more effectively improved. In addition, the colorant may contain other colorants in addition to the metal oxide and the carbon black. Examples of the other colorant include nigrosine and activated carbon.

Examples of the metal oxide include copper oxide, ferroferric oxide, manganese dioxide, titanium oxide, zinc oxide, zirconium oxide, barium titanate, potassium titanate, iron titanate, copper-chromium oxide, copper-manganese oxide, copper-iron-manganese oxide, copper-chromium-manganese oxide, copper-iron-chromium oxide, and titanium black. Among them, the metal species of the metal oxide is more preferably a metal oxide selected from copper, iron and manganese. By selecting the above-mentioned kind as the colorant, the coloring stability becomes good.

The colorant is fine particles, and the lower limit of the primary average particle diameter of the colorant is not particularly limited, but is preferably 0.01 μm or more, and more preferably 0.1 μm or more. The primary average particle diameter of the colorant is preferably 15 μm or less, more preferably 12 μm or less, still more preferably 10 μm or less, yet more preferably 5 μm or less, yet more preferably less than 5 μm, yet more preferably less than 3 μm, particularly preferably less than 1 μm, and most preferably less than 0.5. mu.m. By setting the primary average particle diameter of the colorant within the above range, the visibility of the adhesive sheet can be more effectively improved.

The content of the colorant is preferably 0.01 part by mass or more, more preferably 0.1 part by mass or more, and still more preferably 0.2 part by mass or more, per 100 parts by mass of the acrylic polymer. The content of the colorant is preferably 10 parts by mass or less, and more preferably 5 parts by mass or less, per 100 parts by mass of the acrylic polymer.

Further, the colorant is preferably mixed with the acrylic polymer in a state of being dispersed in the dispersion resin. Examples of the dispersion resin include polyester resins, polyurethane resins, acrylic resins, and polyether resins.

(ultraviolet absorber)

The adhesive sheet of the present invention may contain an ultraviolet absorber. In the case where the adhesive sheet contains an ultraviolet absorber, the ultraviolet transmittance of the adhesive sheet can be suppressed to be low. Therefore, deterioration of the adherend to which the pressure-sensitive adhesive sheet is bonded due to ultraviolet rays can be suppressed.

The ultraviolet absorber may be selected from ultraviolet absorbers having an absorption maximum wavelength in the ultraviolet region. In the present invention, it is particularly preferable to use an ultraviolet absorber having a maximum absorption wavelength at a wavelength of 350nm or more. Examples of the ultraviolet absorber having a maximum absorption wavelength at a wavelength of 350nm or more include those represented by the following general formula (1) or (2).

[ solution 3]

General formula (1)

In the above formula, R¹Represents a hydrogen atom, a halogen atom, an alkoxy group having 1 to 4 carbon atoms, a nitro group or a cyano group, R²Represents a hydrogen atomA carbon atom number of 1 to 8, R³Represents an alkyl system structure.

[ solution 4]

General formula (2)

In the above formula, R⁴、R⁵And R⁶Is a hydrogen atom, a hydroxyl group, an alkyl system structure or a halogen atom, and R⁴、R⁵And R⁶Not all are hydrogen atoms. The alkyl system structure is a concept including a substituent group such as a substituted or unsubstituted alkyl group or a substituted or unsubstituted alkoxy group, which is mainly an alkyl group.

Among them, an ultraviolet absorber which has improved compatibility by introducing an alkyl group having a large molecular weight into an aromatic ring of a basic skeleton and shows a liquid or oil state at 23 ℃ can be particularly preferably used. Here, the expression of liquid or oil at 23 ℃ means: even if the diluent solvent is not present, the ultraviolet absorber alone has fluidity.

As the ultraviolet absorber, commercially available ones can be used. Examples of commercially available products include: a triazine-based ultraviolet absorber (Tinuvin477) manufactured by BASF JAPAN LTD; ADK STAB LA-46 and ADK STAB LA-F70, manufactured by ADEKA K.K.); benzotriazole-based ultraviolet absorbers (Tinuvin109, Tinuvin384-2, Tinuvin PS), and the like.

When the pressure-sensitive adhesive sheet contains an ultraviolet absorber, the content of the ultraviolet absorber is preferably 0.1 to 10 parts by mass, more preferably 0.5 to 8 parts by mass, and still more preferably 1 to 6 parts by mass, per 100 parts by mass of the acrylic polymer. The content of the ultraviolet absorber is preferably adjusted so that the ultraviolet transmittance at a wavelength of 380nm is less than 10%. That is, the ultraviolet transmittance of the pressure-sensitive adhesive sheet at a wavelength of 380nm is preferably less than 10%. The ultraviolet absorber can be used alone in1 kind, can also be combined with more than 2, in the case of using more than 2, preferably the total mass is in the above range.

(crosslinking agent)

The adhesive composition forming the adhesive sheet of the present invention may contain a crosslinking agent. The crosslinking agent may be appropriately selected in consideration of reactivity with the crosslinkable functional group of the acrylic polymer. The crosslinking agent can be selected from known crosslinking agents such as isocyanate compounds, epoxy compounds, oxazoline compounds, aziridine compounds, metal chelate compounds, and butylated melamine compounds. Among them, isocyanate compounds and epoxy compounds are preferably used because they can easily crosslink the hydroxyl group-containing (meth) acrylate. That is, the crosslinking agent is preferably at least 1 selected from the group consisting of a bifunctional or higher epoxy compound and a bifunctional or higher isocyanate compound, and more preferably a bifunctional or higher isocyanate compound.

Examples of the isocyanate compound include toluene diisocyanate, xylylene diisocyanate, hexamethylene diisocyanate, and isophorone diisocyanate. Examples of commercially available products include a tolylene diisocyanate compound (Coronatel, manufactured by Tosoh corporation) and a xylylene diisocyanate compound (TakenateD-110N, manufactured by Mitsui chemical Co., Ltd.).

Examples of the epoxy compound include ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, glycerol diglycidyl ether, neopentyl glycol diglycidyl ether, 1, 6-hexanediol diglycidyl ether, tetraglycidyl xylylenediamine, 1, 3-bis (N, N-diglycidylaminomethyl) cyclohexane, trimethylolpropane polyglycidyl ether, diglycerol polyglycidyl ether, polyglycerol polyglycidyl ether, and sorbitol polyglycidyl ether.

Examples of commercially available products include 1, 3-bis (N, N-diglycidylaminomethyl) benzene (Mitsubishi gas chemical corporation, TETRAD-X), 1, 3-bis (N, N-diglycidylaminomethyl) cyclohexane (Mitsubishi gas chemical corporation, TETRAD-C), and the like.

The content of the crosslinking agent in the adhesive composition is appropriately selected depending on the desired adhesiveness and the like, but is preferably 0.01 to 5 parts by mass, more preferably 0.1 to 3 parts by mass, based on 100 parts by mass of the acrylic polymer. By setting the content of the crosslinking agent within the above range, the processability (punching processability, removal processability, etc.) of the adhesive sheet can be further improved. Further, as the crosslinking agent, can be used alone, can also be used in combination of 2 or more, in the case of using 2 or more, preferably to make the total mass in the above range.

(polyfunctional monomer)

In the case where the adhesive sheet of the present invention is a semi-cured adhesive sheet, the adhesive sheet preferably further contains a polyfunctional monomer. The polyfunctional monomer is a monomer having 2 or more reactive double bonds in the molecule. Among them, the polyfunctional monomer is preferably a monomer having 2 or more and less than 5 reactive double bonds, and more preferably a monomer having 2 or more and less than 4 reactive double bonds.

The polyfunctional monomer is preferably a polyfunctional monomer having a bisphenol skeleton in1 molecule. By using a polyfunctional monomer having a bisphenol skeleton in1 molecule, the hardness of the pressure-sensitive adhesive sheet after post-curing can be more effectively improved. This can suppress the stickiness (tackiness) of the edge face of the pressure-sensitive adhesive sheet after post-curing to a low level, and can improve the workability of the pressure-sensitive adhesive sheet.

Examples of the polyfunctional monomer having a bisphenol skeleton in1 molecule include diacrylate esters of bisphenol a diglycidyl ether, propoxylated diacrylate esters of bisphenol a, and diacrylate esters of bisphenol F diglycidyl ether.

As the polyfunctional monomer, commercially available products can be used. Examples of commercially available products include a difunctional monomer M211B (bisphenol A ethylene oxide-modified diacrylate) manufactured by Toyo Synthesis, a difunctional monomer M08 (bisphenol F ethylene oxide-modified diacrylate) manufactured by Toyo Synthesis, and a difunctional monomer A-BPP-3 (propoxylated bisphenol A diacrylate) manufactured by Xinzhou chemical Co.

In addition, the polyfunctional monomer may be a polyfunctional monomer having an alkylene glycol group in1 molecule. The glass transition temperature (Tg) of the homopolymer at the time of polymerizing such a polyfunctional monomer is preferably 150 ℃ or lower, more preferably 100 ℃ or lower. The glass transition temperature (Tg) of the homopolymer at the time of polymerizing a polyfunctional monomer having an alkylene glycol group in1 molecule is preferably-35 ℃ or higher, more preferably-10 ℃ or higher.

Examples of such a polyfunctional monomer include polyethylene glycol diacrylate and trimethylolpropane oxypropylene-modified triacrylate.

As the polyfunctional monomer, commercially available products can be used. Examples of commercially available products include a trifunctional monomer M321 (trimethylolpropane propylene oxide modified triacrylate, Tg50 ℃ C.) and a difunctional monomer M240 (polyethylene glycol diacrylate, Tg50 ℃ C.) manufactured by Toyo Synthesis.

The content of the polyfunctional monomer is preferably 1 to 40 parts by mass, and more preferably 5 to 30 parts by mass, based on 100 parts by mass of the acrylic polymer. The polyfunctional monomer may be used alone in1 kind, or may be used in combination in 2 or more kinds, and when 2 or more kinds are used in combination, the total mass is preferably within the above range. By setting the content of the polyfunctional monomer within the above range, the hardness of the pressure-sensitive adhesive sheet after post-curing can be more effectively improved, and the processability of the pressure-sensitive adhesive sheet can be improved.

(monofunctional monomer)

In the case where the adhesive sheet of the present invention is a semi-cured adhesive sheet, the adhesive sheet preferably further contains a monofunctional monomer. A monofunctional monomer is a monomer having 1 reactive double bond in the molecule.

Examples of the monofunctional monomer include isobornyl acrylate, isostearyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, benzyl methacrylate, N-acryloyloxyethylhexahydrophthalimide, acrylamide, N-dimethylacrylamide, N-diethylacrylamide, acryloylmorpholine, and vinylpyrrolidone. Examples of commercially available products of monofunctional monomers include IBXA manufactured by Osaka organic chemical industries, ISTA manufactured by Osaka organic chemical industries, and Diethylacrylamide (DEAA) manufactured by KJ Chemicals Corporation, Japan.

The content of the monofunctional monomer is preferably 1 to 40 parts by mass, and more preferably 5 to 30 parts by mass, based on 100 parts by mass of the acrylic polymer. The monofunctional monomer can be used alone in1 kind, can also be used in combination with 2 or more, in the case of using 2 or more, preferably to make the total mass within the above range.

(polymerization initiator)

In the case where the adhesive sheet of the present invention is a semi-cured adhesive sheet, the adhesive sheet preferably contains a polymerization initiator. The polymerization initiator is preferably an initiator which initiates polymerization of the polyfunctional monomer and/or the monofunctional monomer by irradiation with active energy rays, and more preferably an initiator which initiates polymerization of the polyfunctional monomer and the monofunctional monomer by irradiation with active energy rays. As the polymerization initiator, a known polymerization initiator such as a photopolymerization initiator can be used.

Here, the "active energy ray" refers to a ray having an energy quantum in an electromagnetic wave or a charged particle ray, and examples thereof include an ultraviolet ray, an electron beam, a visible ray, an X-ray, an ion ray, and the like. Among them, from the viewpoint of versatility, ultraviolet rays or electron beams are preferable, and ultraviolet rays are particularly preferable.

Examples of the polymerization initiator include acetophenone-based initiators, benzoin ether-based initiators, benzophenone-based initiators, hydroxyalkyl phenone-based initiators, thioxanthone-based initiators, amine-based initiators, and acylphosphine oxide-based initiators.

Specific examples of the acetophenone initiator include diethoxyacetophenone and benzildimethylketal.

Specific examples of the benzoin ether initiator include benzoin and benzoin methyl ether.

Specific examples of the benzophenone initiator include benzophenone and methyl o-benzoylbenzoate.

Specific examples of the hydroxyalkyl phenone initiator include 1-hydroxy-cyclohexyl-phenyl-ketone (available as IRGACURE184 from BASF JAPAN LTD.) and the like.

Specific examples of the thioxanthone initiator include 2-isopropylthioxanthone and 2, 4-dimethylthioxanthone.

Specific examples of the amine initiator include triethanolamine and ethyl 4-dimethylbenzoate.

Specific examples of the acylphosphine oxide initiator include phenylbis (2,4, 6-trimethylbenzoyl) phosphine oxide (available as IRGACURE819, manufactured by BASF JAPAN LTD.) and the like.

The content of the polymerization initiator is preferably 0.01 to 10 parts by mass, and more preferably 0.1 to 5 parts by mass, based on 100 parts by mass of the acrylic polymer. The polymerization initiator may be used alone in1 kind, or may be used in combination in 2 or more kinds, and when 2 or more kinds are used in combination, the total mass is preferably within the above range.

(solvent)

The adhesive composition forming the adhesive sheet of the present invention may contain a solvent. In this case, the solvent is used for improving the coating suitability of the adhesive composition. Examples of the solvent include: hydrocarbons such as hexane, heptane, octane, toluene, xylene, ethylbenzene, cyclohexane, and methylcyclohexane; halogenated hydrocarbons such as dichloromethane, trichloroethane, trichloroethylene, tetrachloroethylene, and dichloropropane; alcohols such as methanol, ethanol, propanol, isopropanol, butanol, isobutanol, and diacetone alcohol; ethers such as diethyl ether, diisopropyl ether, dioxane and tetrahydrofuran; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, isophorone, and cyclohexanone; esters such as methyl acetate, ethyl acetate, butyl acetate, isobutyl acetate, amyl acetate, ethyl butyrate, and the like; polyhydric alcohols and derivatives thereof such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, propylene glycol monoethyl ether, and propylene glycol monomethyl ether acetate.

The content of the solvent in the adhesive composition is not particularly limited, and is preferably 25 to 500 parts by mass, and more preferably 30 to 400 parts by mass, based on 100 parts by mass of the acrylic polymer.

The content of the solvent is preferably 10 to 90% by mass, and more preferably 20 to 80% by mass, based on the total mass of the binder composition. The solvent may be used singly or in combination of 1 or more, and when 2 or more are used in combination, the total mass is preferably within the above range.

(other Components)

The adhesive sheet may contain other components than those described above within a range not impairing the effects of the present invention. As the other components, components known as additives for adhesives can be cited. The solvent may be selected from, for example, plasticizers, antioxidants, metal preservatives, tackifiers, silane coupling agents, light stabilizers such as hindered amine compounds, and the like, as required.

Examples of the plasticizer include: vinyl carboxylates such as vinyl acetate, vinyl propionate, vinyl butyrate, vinyl caproate, vinyl caprylate, vinyl caprate, vinyl laurate, vinyl myristate, vinyl palmitate, vinyl stearate, vinyl cyclohexanecarboxylate, and vinyl benzoate; styrene, and the like.

Examples of the antioxidant include phenol-based antioxidants, amine-based antioxidants, lactone-based antioxidants, phosphorus-based antioxidants, and sulfur-based antioxidants. These antioxidants may be used alone in1 kind, or may be used in combination in 2 or more kinds.

As the metal corrosion inhibitor, a benzotriazole-based resin is cited as a preferable example in view of high compatibility and effect of the binder.

Examples of the tackifier include rosin-based resins, terpene-phenol-based resins, coumarone-indene-based resins, styrene-based resins, xylene-based resins, phenol-based resins, and petroleum resins.

Examples of the silane coupling agent include mercaptoalkoxysilane compounds (e.g., mercapto-substituted alkoxy oligomers), and the like.

< method for producing adhesive sheet >

The method for producing the pressure-sensitive adhesive sheet of the present invention preferably includes a step of applying the pressure-sensitive adhesive composition to a release sheet to form a coating film.

The application of the adhesive composition can be performed using a known application device. Examples of the coating device include a blade coater, an air knife coater, a roll coater, a bar coater, a gravure coater, a microgravure coater, a bar blade coater, a lip coater, a die coater, and a curtain coater.

The method for producing the adhesive sheet preferably includes a step of heating the coating film. In this case, a known heating device such as a heating furnace or an infrared lamp may be used to heat the coating film formed by applying the adhesive composition.

In the case where the adhesive sheet is a semi-cured adhesive sheet, the method for producing an adhesive sheet preferably includes a step of making the coating film into a semi-cured product. For example, the coating film can be heated to react the acrylic polymer and the crosslinking agent, thereby producing a cured product (adhesive sheet) in a semi-cured state. That is, since the polymerization reaction of the monomer based on the polymerization initiator does not proceed in the coating film during heating, it is not at all possible to proceed, and at least a part of the acrylic monomer and the polymerization initiator are included in the adhesive sheet in an unreacted state.

In order to semi-cure the adhesive composition, it is preferable to perform a curing treatment in which the adhesive sheet is left to stand at a certain temperature for a certain period of time after the solvent is removed after application. The aging treatment can be carried out, for example, by leaving it at 23 ℃ for 7 days.

The semi-cured pressure-sensitive adhesive sheet can be post-cured by irradiation with active energy rays after being bonded to an adherend such as a substrate. That is, the semi-cured adhesive sheet is a 2-stage curing type adhesive sheet, and has an adhesive layer semi-cured by heat only before bonding, and the adhesive layer is post-cured by active energy rays after bonding.

< method of using adhesive sheet >

In the method for using the pressure-sensitive adhesive sheet of the present invention, the pressure-sensitive adhesive sheet is preferably brought into contact with the surface of an adherend. In the case where the adhesive sheet is a semi-cured adhesive sheet, it is preferable that: the pressure-sensitive adhesive sheet is bonded to an adherend in a semi-cured state, and the pressure-sensitive adhesive sheet is irradiated with active energy rays to be cured.

< use of adhesive sheet >

The adhesive sheet of the present invention is used for bonding a transparent member. As the transparent member, there can be mentioned: a window of a building, a side window glass of a vehicle, or the like; optical members such as touch panels and image display devices. Among these, the pressure-sensitive adhesive sheet of the present invention is preferably used for bonding optical members. When the adhesive sheet of the present invention is used for bonding optical members, the adhesive sheet is preferably used for bonding to an anti-scattering film bonded to each component member in an optical product or to the outermost cover glass, and particularly preferably used for bonding to a touch panel. Examples of the constituent member of the touch panel include an ITO film in which an ITO film is provided on a transparent resin film, an ITO glass in which an ITO film is provided on a surface of a glass plate, a transparent conductive film in which a conductive polymer is coated on a transparent resin film, a hard coat film, and a fingerprint resistant film. Examples of the constituent members of the image display device include an antireflection film, an alignment film, a polarizing film, a retardation film, and a brightness enhancement film used in a liquid crystal display device.

Examples of the material used for these members include glass, polycarbonate, polyethylene terephthalate, polymethyl methacrylate, polyethylene naphthalate, cycloolefin polymer, triacetyl cellulose, polyimide, cellulose acylate, and the like.

(laminated body)

The present invention relates to a laminate including a surface layer, a pressure-sensitive adhesive layer, and a layer including a conductive member in this order. Here, the adhesive layer includes an acrylic polymer and a colorant. The laminate of the present invention has the above-described structure, and therefore has excellent design properties. Further, the laminate of the present invention has the above-described structure, and therefore, can suppress the perspective of the layer including the conductive member.

Fig. 2 is a sectional view illustrating the structure of the laminate of the present invention. As shown in fig. 2, the laminate 10 includes a surface layer 13, a pressure-sensitive adhesive layer 14, and a layer 16 including a conductive member in this order. Further, another layer may be provided between the layers, but the surface layer 13 is preferably disposed adjacent to the adhesive layer 14, and the adhesive layer 14 is preferably also disposed adjacent to the layer 16 containing the conductive member.

(adhesive layer)

In the laminate, the adhesive layer contains an acrylic polymer and a colorant. In the present invention, the adhesive layer contains a colorant, whereby the design can be improved when the laminate is produced. For example, even in a member having a stepped portion in the surface layer, the stepped portion and the non-stepped portion can be perceived as a unified body. This improves the sense of unity of the entire laminate, and improves the design.

In addition, in the laminate, the colorant is contained in the adhesive layer, whereby the transparency of the layer containing the conductive member can be suppressed. For example, when the opening pattern of the conductive member (stripe pattern from the conductive member) is not observed when the laminate is visually observed from the surface layer side, it can be evaluated that the see-through is suppressed.

The total light transmittance of the pressure-sensitive adhesive layer in the laminate is preferably 5% or more, more preferably 10% or more, still more preferably 20% or more, further preferably 30% or more, and particularly preferably 40% or more. The total light transmittance of the pressure-sensitive adhesive layer in the laminate is preferably 90% or less, more preferably 86% or less, more preferably 80% or less, further preferably 75% or less, and particularly preferably 70% or less. By setting the total light transmittance of the pressure-sensitive adhesive layer within the above range, the design property and the see-through preventing effect of the laminate can be more effectively improved.

The lower limit of the haze of the pressure-sensitive adhesive layer in the laminate is not particularly limited, but is preferably 0.1% or more. The haze of the pressure-sensitive adhesive layer in the laminate is preferably 20% or less, more preferably 15% or less, still more preferably 10% or less, further preferably 8% or less, and particularly preferably 6% or less. When the haze of the pressure-sensitive adhesive layer is within the above range, the degree of black color development of a display or the like can be increased, and visibility can be maintained.

The product of the total light transmittance and the haze value of the pressure-sensitive adhesive layer in the laminate is preferably 300 or less, more preferably 170 or less, still more preferably 165 or less, yet more preferably 160 or less, still more preferably 155 or less, and particularly preferably 150 or less. The product of the total light transmittance and the haze value of the pressure-sensitive adhesive layer in the laminate is preferably 10 or more, and more preferably 30 or more. Among them, the total light transmittance of the pressure-sensitive adhesive layer is preferably 40% or more and the haze is preferably 6% or less, and the total light transmittance of the pressure-sensitive adhesive layer is preferably 90% or less and the haze is preferably 0.1% or more. By setting the product of the total light transmittance and the haze value to the above range and setting the total light transmittance and the haze of the pressure-sensitive adhesive layer to predetermined ranges, the design property and the see-through preventing effect of the laminate can be more effectively improved.

The thickness of the pressure-sensitive adhesive layer in the laminate is preferably 1 μm or more, more preferably 10 μm or more, and still more preferably 20 μm or more. The thickness of the pressure-sensitive adhesive layer in the laminate is preferably 5000 μm or less, more preferably 3000 μm or less, and still more preferably 1000 μm or less. By setting the thickness of the pressure-sensitive adhesive layer to the upper limit or less, it is possible to prevent water vapor from entering from the end portion and improve durability. On the other hand, by setting the thickness of the pressure-sensitive adhesive layer to the above-described lower limit or more, the pressure-sensitive adhesive layer can be easily handled, and the level difference filling performance can be further improved.

The pressure-sensitive adhesive layer may be a single-layer pressure-sensitive adhesive layer or a multilayer pressure-sensitive adhesive layer in which a plurality of pressure-sensitive adhesive layers are stacked. The pressure-sensitive adhesive layer may be a multilayer pressure-sensitive adhesive layer in which another pressure-sensitive adhesive layer is laminated between the pressure-sensitive adhesive layer and the pressure-sensitive adhesive layer, or a multilayer pressure-sensitive adhesive layer in which a support is laminated between the pressure-sensitive adhesive layer and the pressure-sensitive adhesive layer. In the case where the adhesive layer has a support, the support is preferably a transparent support. As the support, a general film used in the optical field can be used.

The gel fraction of the pressure-sensitive adhesive layer is preferably 50% by mass or more, more preferably 60% by mass or more, and still more preferably 65% by mass or more. The gel fraction of the pressure-sensitive adhesive layer is preferably 99% by mass or less. By setting the gel fraction within the above range, durability and adhesive force can be both satisfied.

The gel fraction of the pressure-sensitive adhesive layer is a value measured by the following method. First, about 0.1g of an adhesive layer was collected in a sample bottle, and 30ml of ethyl acetate was added thereto and shaken for 24 hours. Thereafter, the content of the sample bottle was separated by filtration through a 150-mesh stainless steel wire mesh, and the residue on the wire mesh was dried at 100 ℃ for 1 hour to measure the dry mass (g). From the obtained dry mass, the gel fraction was calculated according to the following formula 1.

Gel fraction (%) (dry mass/collected mass of adhesive layer) × 100 · equation 1

The adhesive layer in the laminate contains the acrylic polymer and the colorant as described above. This can improve the design and see-through prevention of the laminate. The pressure-sensitive adhesive layer in the laminate may contain the above-mentioned ultraviolet absorber, crosslinking agent, and the like.

(surface layer)

The surface layer is a layer of the laminate provided on the outermost surface, and for example, in the case where the laminate is assembled to a display or the like, the surface layer is a layer provided on the outermost surface on the side to be visually recognized. The surface layer can be a surface protection film or a decorative film.

The surface layer is preferably a glass layer or a resin layer. The glass layer is not particularly limited, and examples thereof include chemically strengthened glass, alkali-free glass, quartz glass, soda-lime glass, barium-strontium-containing glass, aluminosilicate glass, lead glass, borosilicate glass, barium borosilicate glass, and the like. The resin layer is not particularly limited, and examples thereof include acrylic sheets and polycarbonate sheets made of polymethyl methacrylate or the like. Among them, the surface layer is more preferably a glass layer.

The surface layer may have a level difference on at least one side. For example, the adhesive layer-attached side of the surface layer may have a frame-like level difference. In this case, the height difference is preferably 1 to 50 μm, more preferably 5 to 40 μm, and still more preferably 10 to 30 μm. The thickness of the step is preferably 50% or less, more preferably 40% or less, and still more preferably 30% or less, based on the thickness of the pressure-sensitive adhesive layer. By setting the height difference provided in the surface layer to the above condition, the occurrence of floating and bubbles in the height difference portion between the adhesive layer and the surface layer can be suppressed, and the laminate can exhibit excellent design properties.

Further, a functional layer such as a hard coat layer, an antireflection layer, or an antiglare layer may be provided on one or both surfaces of the surface layer.

(layer comprising conductive Member)

The layer containing a conductive member contains a conductive member such as an ITO film. Among them, the layer containing the conductive member is preferably a touch sensor. The touch sensor is preferably a member including a display body module and a conductive member. Examples of the display module include a Liquid Crystal (LCD) module, a Light Emitting Diode (LED) module, an organic electroluminescence (organic EL) module, and electronic paper.

Examples of the conductive member include conductive members composed of: metals such as platinum, gold, silver, and copper; oxides such as tin oxide, indium oxide, cadmium oxide, zinc oxide, and zinc oxide; tin-doped indium oxide (ITO), zinc oxide-doped indium oxide, fluorine-doped indium oxide, antimony-doped tin oxide, fluorine-doped tin oxide, aluminum-doped zinc oxide, and the like; non-oxidizing compounds such as chalcogenides, lanthanum hexaboride, titanium nitride, and titanium carbide. Among them, from the viewpoint of practicality, a conductive member made of tin-doped indium oxide (ITO), copper, or silver is preferable.

< method for producing laminate >

The present invention may relate to a laminate comprising the pressure-sensitive adhesive sheet and an adherend (transparent member), and a method for producing a laminate comprising the pressure-sensitive adhesive sheet and the adherend. In the case of producing a laminate, a step of bonding a pressure-sensitive adhesive sheet to an adherend is included. The method for producing the laminate preferably includes a step of forming a pressure-sensitive adhesive sheet constituting the pressure-sensitive adhesive layer, a step of bonding the surface layer to one surface of the pressure-sensitive adhesive sheet, and a step of bonding the layer including the conductive member to the other surface of the pressure-sensitive adhesive sheet. In the case where the pressure-sensitive adhesive sheet is a semi-cured pressure-sensitive adhesive sheet, the laminate is preferably a laminate formed by irradiating 2 adherends with an active energy ray in a state of being bonded to the semi-cured pressure-sensitive adhesive sheet and curing the irradiated objects.

The step of forming the pressure-sensitive adhesive sheet preferably includes a step of applying the pressure-sensitive adhesive composition to a release sheet to form a coating film. The application of the adhesive composition can be performed using a known application device. Examples of the coating device include a blade coater, an air knife coater, a roll coater, a bar coater, a gravure coater, a microgravure coater, a bar blade coater, a lip coater, a die coater, and a curtain coater.

The step of forming the pressure-sensitive adhesive sheet preferably includes a step of heating the coating film. In this case, a known heating device such as a heating furnace or an infrared lamp may be used to heat the coating film formed by applying the adhesive composition. After the coating film is heated, the pressure-sensitive adhesive layer may be subjected to a curing treatment in which the pressure-sensitive adhesive layer is left to stand at a certain temperature for a certain period of time. The aging treatment can be carried out, for example, by leaving it at 23 ℃ for 7 days.

In the step of bonding the surface layer to one surface of the pressure-sensitive adhesive sheet, the surface layer is bonded to the pressure-sensitive adhesive surface exposed by peeling the release sheet from the pressure-sensitive adhesive sheet.

In the step of bonding the layer containing the conductive member to the other surface of the adhesive sheet, the layer containing the conductive member is bonded to the adhesive surface exposed by peeling the release sheet from the adhesive sheet. After the lamination, the laminate may be subjected to autoclave treatment. In the autoclave treatment, the respective members can be closely attached to each other by holding the autoclave at 40 ℃ for 30 minutes under 5 atmospheres, for example.

In the case where the adhesive sheet is a semi-cured adhesive sheet, the method for producing a laminate preferably includes the steps of: after the adhesive sheet is adhered to an adherend in a semi-cured state, the adhesive sheet is cured by irradiation with active energy rays. Since the adhesive sheet is in a semi-cured state before being irradiated with active energy rays, initial adhesion to a substrate is good. In this way, when the pressure-sensitive adhesive sheet is bonded to an adherend and then cured by active energy rays, the cohesive strength of the pressure-sensitive adhesive sheet is improved, and the adhesiveness to the adherend is improved. In addition, the post-cured adhesive sheet also has excellent processability.

The active energy ray may be ultraviolet ray, electron beam, visible ray, X-ray, ion ray, or the like, and may be appropriately selected according to the polymerization initiator contained in the pressure-sensitive adhesive sheet. Among them, from the viewpoint of versatility, ultraviolet rays or electron beams are preferable, and ultraviolet rays are particularly preferable.

As the light source of the ultraviolet rays, for example, a high-pressure mercury lamp, a low-pressure mercury lamp, an ultrahigh-pressure mercury lamp, a metal halide lamp, a carbon arc, a xenon arc, an electrodeless ultraviolet lamp, or the like can be used.

As the electron beam, for example, an electron beam emitted from various electron beam accelerators such as a Cockcroft Walton type, a Vande Graaff type, a resonance transformer type, an insulated core transformer type, a line type, a Dynamitron type, and a high frequency type can be used.

The ultraviolet irradiation power is preferably such that the cumulative light amount is 100 to 10000mJ/cm²More preferably, the cumulative light amount is 500 to 5000mJ/cm²。

Examples

Hereinafter, the features of the present invention will be described in more detail by way of examples and comparative examples. The materials, amounts used, ratios, treatment contents, treatment steps and the like shown in the following examples can be changed as appropriate without departing from the gist of the present invention. Therefore, the scope of the present invention should not be construed as being limited to the specific examples shown below.

The pressure-sensitive adhesive sheets of examples 1 to 8 and comparative example 1 were produced and evaluated by the following methods.

< Synthesis of acrylic Polymer A1 >

Acrylic polymer a1 was made by solution polymerization in ethyl acetate. Butyl Acrylate (BA), 2-ethylhexyl methacrylate (2EHMA), Ethyl Acrylate (EA), 2-hydroxyethyl methacrylate (2HEMA) and Acrylic Acid (AA) were added in a mass ratio of 85: 5: 4: 4: 2, and AIBN (azobisisobutyronitrile) as a radical polymerization initiator was dissolved in the solution. The solution was heated to 60 ℃ to carry out random copolymerization to obtain an acrylic polymer A1. A35 mass% solution of the acrylic polymer A1 had a solution viscosity of 3,650 mPas at 23 ℃. The acid value of the acrylic polymer A1 was 1.6 mgKOH/g.

< Synthesis of acrylic Polymer B1 >

The acrylic polymer B1 was made by solution polymerization in ethyl acetate. Butyl Acrylate (BA) and 2-hydroxyethyl acrylate (2HEA) are mixed according to the mass ratio of 70: 30, and AIBN (azobisisobutyronitrile) as a radical polymerization initiator was dissolved in the solution. The solution was heated to 60 ℃ to carry out random copolymerization to obtain an acrylic polymer B1. A35% by mass solution of this acrylic polymer B1 had a solution viscosity of 6,400 mPas at 23 ℃. The acid value of the acrylic polymer B1 was 0.0 mgKOH/g.

< Synthesis of acrylic Polymer C1 >

The acrylic polymer C1 was made by solution polymerization in ethyl acetate. Butyl Acrylate (BA), Methyl Acrylate (MA), Methyl Methacrylate (MMA) and acrylic acid were added in a mass ratio of 87: 1: 4: 8, and dissolving AIBN (azobisisobutyronitrile) as a radical polymerization initiator in the solution. The solution was heated to 60 ℃ to carry out random copolymerization to obtain an acrylic polymer C1. A35 mass% solution of the acrylic polymer C1 had a solution viscosity of 4,200 mPas at 23 ℃. The acid value of the acrylic polymer C1 was 60.0 mgKOH/g.

< Synthesis of acrylic Polymer D1 >

The acrylic polymer D1 was made by solution polymerization in ethyl acetate. Mixing a 2-methoxyethyl acrylate Monomer (MEA), a 2-hydroxyethyl acrylate monomer (2HEA), Methyl Methacrylate (MMA), Dimethylacrylamide (DMAA) and Butyl Acrylate (BA) according to a mass ratio of 70: 10: 10: 5: 5, and dissolving AIBN (azobisisobutyronitrile) as a radical polymerization initiator in the solution. The solution was heated to 60 ℃ to carry out random copolymerization to obtain an acrylic polymer D1. A35% by mass solution of this acrylic polymer D1 had a solution viscosity of 2,000 mPas at 23 ℃. Further, the acid value of the acrylic polymer D1 was 0.0 mgKOH/g.

(example 1)

To 100 parts by mass of acrylic polymer A1, 0.1 part by mass of N, N, N ', N' -tetraglycidyl-1, 3-benzenebis (methylamine) (manufactured by Mitsubishi gas chemical Co., Ltd., TETRAD-X) as a crosslinking agent, 10 parts by mass of diethylacrylamide (manufactured by KJ Chemicals Corporation, DEAA) as a monofunctional monomer, 10 parts by mass of bisphenol A ethylene oxide-modified diacrylate (manufactured by Toya Corporation, ARONIX M211B) as a polyfunctional monomer, 0.3 part by mass of 1-hydroxy-cyclohexyl-phenyl-ketone (manufactured by BASF JAPAN Corporation, IRGACURE) as a polymerization initiator, and 0.6 part by mass of copper, iron, manganese-based oxide-based pigment (manufactured by DARIFU Kogyo Co., Ltd., TM BLACK 3550) as a coloring agent were added, ethyl acetate was added as a solvent so that the solid content concentration became 30 mass%, to obtain a pressure-sensitive adhesive composition.

The above adhesive composition was applied to a first release sheet (a heavy-duty release Film, a polyethylene terephthalate Film produced by Teijin Dupont Film co., ltd.) subjected to a release treatment). The coating was carried out using a Doctor Blade YD model manufactured by Gekko Seiko K.K. so that the thickness after drying was 25 μm. Thereafter, the sheet was dried at 100 ℃ for 3 minutes by a hot air dryer to remove the solvent, thereby forming a pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer in a semi-cured state.

A second release sheet (a light release Film, a Teijin Dupont Film) which had been subjected to a release treatment and had a higher peel strength than the first release sheet was attached to one side of the pressure-sensitive adhesive sheet, to obtain the pressure-sensitive adhesive sheet of example 1 as a pressure-sensitive adhesive sheet with a release sheet.

(example 2)

An adhesive composition and a pressure-sensitive adhesive sheet with a release sheet were obtained in the same manner as in example 1, except that the colorant was changed to 0.4 parts by mass of carbon Black (polylac a 903Black, manufactured by toyoyo color co., ltd.).

(example 3)

To 100 parts by mass of acrylic polymer B1, 0.5 part by mass of an ethyl acetate solution of a tolylene diisocyanate adduct of trimethylolpropane (available from tokyo co., CoronateL-55E) as a crosslinking agent, 10 parts by mass of diethylacrylamide (available from KJ Chemicals Corporation, DEAA) as a monofunctional monomer, 10 parts by mass of bisphenol a ethylene oxide-modified diacrylate (available from east asian synthesis Corporation, aronii M211B) as a polyfunctional monomer, 0.3 part by mass of 1-hydroxy-cyclohexyl-phenyl-ketone (available from BASF pan LTD., IRGACURE184) as a polymerization initiator, 0.4 part by mass of a copper, iron, manganese-based oxide-based pigment (available from japanese chemical industries, TM BLACK 3550) as a colorant, and ethyl acetate as a solvent was added so that the solid content concentration reached 30% by mass, an adhesive composition was obtained. Except for this, a pressure-sensitive adhesive sheet with a release sheet was obtained in the same manner as in example 1.

(example 4)

An adhesive composition and a release sheet-equipped adhesive sheet were obtained in the same manner as in example 1, except that the main agent was changed to the acrylic polymer C1 and the crosslinking agent was changed to 0.05 parts by mass.

(example 5)

An adhesive composition and a pressure-sensitive adhesive sheet with a release sheet were obtained in the same manner as in example 4, except that the colorant was changed to 0.4 parts by mass of carbon BLACK (polylac a 903BLACK, manufactured by toyoyo color co., ltd.).

(example 6)

To 100 parts by mass of the acrylic polymer a1, 0.1 part by mass of N, N' -tetraglycidyl-1, 3-benzenebis (methylamine) (tradesman ltd., tetra d-X) as a crosslinking agent and 0.5 part by mass of a copper, iron, manganese oxide pigment (TM BLACK 3550, manufactured by daidzein chemical corporation) as a coloring agent were added, and ethyl acetate as a solvent was added so that the solid content concentration became 30% by mass to obtain a pressure-sensitive adhesive composition. Except for this, a pressure-sensitive adhesive sheet with a release sheet was obtained in the same manner as in example 1.

(example 7)

To 100 parts by mass of acrylic polymer D1, 1 part by mass of adduct-modified hexamethylene diisocyanate (manufactured by Asahi Chemicals K.K., Duranate E405-70B) as a crosslinking agent, 10 parts by mass of diethylacrylamide (manufactured by KJ Chemicals Corporation, DEAA) as a monofunctional monomer, 10 parts by mass of bisphenol A ethylene oxide-modified diacrylate (manufactured by Toyo Kabushiki Kaisha, ARONIX M211B) as a polyfunctional monomer, 0.3 parts by mass of 1-hydroxy-cyclohexyl-phenyl-ketone (manufactured by BASF PAN LTD., IRGACURE184) as a polymerization initiator, 1.1 parts by mass of copper, iron, and manganese-based oxide-based pigment (manufactured by Kagaku Kogyo Co., Ltd., TM BLACK 3550) as a colorant, and ethyl acetate as a solvent was added so that the solid content concentration became 30% by mass, an adhesive composition was obtained. Except for this, a pressure-sensitive adhesive sheet with a release sheet was obtained in the same manner as in example 1.

(example 8)

An adhesive composition and a pressure-sensitive adhesive sheet with a release sheet were obtained in the same manner as in example 7, except that the colorant was changed to 0.4 parts by mass of carbon BLACK (manufactured by Toyo color Co., Ltd., Multilac A903 BLACK) and the crosslinking agent was changed to 0.05 parts by mass.

Comparative example 1

An adhesive composition and a release sheet-equipped adhesive sheet were obtained in the same manner as in example 1, except that no colorant was added.

(evaluation)

< optical characteristics >

A light release separator as a second release sheet was peeled off, and a PET film (Cosmoshine a4300#100, manufactured by toyobo) was bonded to the second release sheet using a hand roller instead of the peeled separator to prepare a laminated film. The laminated film was cut into a size of 50mm in width and 50mm in length, and the first release sheet was peeled off. Next, the exposed adhesive surface was attached to a slide glass (manufactured by sonlang nitre, S9112) using a hand roller. After the glass plate was closely adhered to the autoclave maintained at 40 ℃ under 5 atmospheres for 30 minutes, the cumulative light amount of the examples and comparative examples other than example 6 was 3000mJ/cm from the PET film side²The ultraviolet rays are irradiated.

The total light transmittance and haze of the obtained laminate were measured in accordance with JIS K7150 using an integrating sphere type light transmittance measuring apparatus (NDH-5000, manufactured by Nippon Denshoku industries Co., Ltd.). The measurement was performed 3 times, and the average value was defined as a measurement value.

< gel fraction >

The pressure-sensitive adhesive sheet was cut into pieces of 100mm × 60mm to prepare semi-cured samples for measurement.

The pressure-sensitive adhesive sheet was cut into pieces of 100mm × 60mm so that the cumulative light amount reached 3000mJ/cm from the first release sheet side as a heavy separator²The measurement sample after post-curing was prepared by irradiating ultraviolet rays.

About 0.1g of the adhesive sheet of each measurement sample was taken in a sample bottle, and 30ml of ethyl acetate was added thereto and shaken for 24 hours. Thereafter, the content of the sample bottle was separated by filtration through a 150-mesh stainless steel wire mesh, and the residue on the wire mesh was dried at 100 ℃ for 1 hour to measure the dry mass (g). The gel fraction was determined from the obtained dry mass according to the following formula 1.

Gel fraction (% by mass) × 100 (dry mass/collected mass of adhesive sheet) × 100 formula 1

Design

Samples were prepared in the same manner as in the optical property measurement, and placed on a display showing a black screen for evaluation.

O: looks darker than when nothing is left

X: without change

< visibility >

Samples were prepared in the same manner as in the measurement of optical properties, and placed on a display on which characters were displayed, and evaluated.

O: no feathering or blurring was observed

And (delta): feathering and blurring were observed

X: feathering and blurring were observed and the characters could not be interpreted

< durability >

A light release separator as a second release sheet was peeled off, and a triacetyl cellulose film (FUJITAC TD60UL, 60 μm thick, manufactured by Fuji film Co., Ltd.) was laminated by a hand roller instead of the peeled separator to prepare a laminated film. Cutting the laminated film into a wide widthThe first peel sheet was peeled off at a length of 60mm and 80 mm. Then, the exposed adhesive surface having a width of 60mm and a length of 80mm was adhered to the hard coat surface side of an adherend (polycarbonate sheet with hard coat layer: 1mm in thickness of IUPILON MR58, manufactured by Mitsubishi gas chemical Co., Ltd.) using a 2kg pressure-bonding roller. After the sheet was closely attached to a polycarbonate plate by keeping the sheet in this state in an autoclave at 40 ℃ under 5 atmospheres for 30 minutes, the accumulated light amount from the side of the triacetyl cellulose film was 3000mJ/cm²The test piece was prepared by irradiating the sample with ultraviolet light and leaving the sample at 23 ℃ and 50% relative humidity for 24 hours. Subsequently, the test sample was placed in a dry atmosphere at 105 ℃ and observed for the presence or absence of floating and peeling after 240 hours.

O: no floating and peeling of 1.0mm or more were observed

And (delta): the floating and/or peeling of 1.0mm or more and less than 2.0mm is observed

X: the floating and/or peeling of 2.0mm or more was observed

< decolorization >

A sample was prepared in the same manner as in the measurement of optical properties, and placed at 85 ℃ under an atmosphere of 85% relative humidity, and the total light transmittance after 240 hours was measured. The amount of change was calculated by the following formula based on the total light transmittance of the sample before being left at 85 ℃ and 85% relative humidity, and evaluated by the following evaluation criteria.

Change (%) - (total light transmittance of sample before treatment) - (total light transmittance of sample after treatment)

O: the variation of the total light transmittance is less than +/-10 percent, and the total light transmittance after treatment is less than 85 percent

And (delta): the variation of the total light transmittance is more than 10 percent, and the total light transmittance after treatment is less than 85 percent

X: the variation of the total light transmittance is more than 10%, and the total light transmittance after treatment is more than 85%

< processability >

First, a second release sheet, which is a light release film of the pressure-sensitive adhesive sheet, was peeled off and bonded to a PET film having a thickness of 25 μm.

Then, peeling off asThe first release sheet of the heavy release film was attached to the PC board. A sample having a composition of PET/adhesive sheet/PC was subjected to autoclave treatment (40 ℃, 0.5MPa, 30min), and then the accumulated light amount was 3000mJ/cm from the PET film side²The test sample was obtained by irradiating ultraviolet rays. Next, the end of the test sample was cut with a guillotine cutter, and the cut end was rubbed with a hand from the PC board side so as to peel off the PET film. The separation distance at this time was measured.

O: the peeling distance is less than 0.05mm

And (delta): the peeling distance is more than 0.05mm and less than 0.1mm

X: the peeling distance is more than 0.1mm

[ Table 1]

MO: metal oxides

CB: carbon black

NUV: without post-curing

UV: with post-curing

Adhesive sheets of examples 11 to 16 and comparative example 11 were produced and evaluated by the following methods.

< Synthesis of acrylic Polymer A2 >

Acrylic polymer a2 was made by solution polymerization in ethyl acetate. Butyl Acrylate (BA) and 2-hydroxyethyl acrylate (2HEA) are mixed according to the mass ratio of 70: 30, and AIBN (azobisisobutyronitrile) as a radical polymerization initiator was dissolved in the solution. The solution was heated to 60 ℃ to carry out random copolymerization to obtain an acrylic polymer A2. A35 mass% solution of the acrylic polymer A2 had a solution viscosity of 6,400 mPas at 23 ℃. Further, the acid value of the acrylic polymer A2 was 0.0 mgKOH/g.

< Synthesis of acrylic Polymer B2 >

The acrylic polymer B2 was made by solution polymerization in ethyl acetate. Butyl Acrylate (BA), 2-ethylhexyl methacrylate (2EHMA), Ethyl Acrylate (EA), 2-hydroxyethyl methacrylate (2HEMA) and Acrylic Acid (AA) were added in a mass ratio of 85: 5: 4: 4: 2, and AIBN (azobisisobutyronitrile) as a radical polymerization initiator was dissolved in the solution. The solution was heated to 60 ℃ to carry out random copolymerization to obtain an acrylic polymer B2. A35% by mass solution of this acrylic polymer B2 had a solution viscosity of 3,650 mPas at 23 ℃. The acid value of the acrylic polymer B2 was 1.6 mgKOH/g.

< Synthesis of acrylic Polymer C2 >

The acrylic polymer C2 was made by solution polymerization in ethyl acetate. Butyl Acrylate (BA), Methyl Acrylate (MA), Methyl Methacrylate (MMA) and acrylic acid were added in a mass ratio of 87: 1: 4: 8, and dissolving AIBN (azobisisobutyronitrile) as a radical polymerization initiator in the solution. The solution was heated to 60 ℃ to carry out random copolymerization to obtain an acrylic polymer C2. A35 mass% solution of the acrylic polymer C2 had a solution viscosity of 4,200 mPas at 23 ℃. The acid value of the acrylic polymer C2 was 60.0 mgKOH/g.

(example 11)

To 100 parts by mass of the acrylic polymer a2, 0.5 part by mass of an isocyanate-based crosslinking agent (Coronate L-55E, manufactured by tokyo co., LTD.), 2 parts by mass of a triazine-based ultraviolet absorber (Tinuvin477, manufactured by BASF JAPAN LTD.) as an ultraviolet absorber, and 0.06 part by mass of a copper, iron, and manganese-based oxide-based pigment (TM BLACK 3550, manufactured by daidz corporation) as a coloring agent were added, and ethyl acetate as a solvent was added so that the solid content concentration became 35% by mass, to obtain an adhesive composition.

The above adhesive composition was applied to a first release sheet (a heavy-duty release Film, a polyethylene terephthalate Film produced by Teijin Dupont Film co., ltd.) subjected to a release treatment). The coating was carried out using a Doctor Blade YD model manufactured by Gekko Seiko K.K., so that the thickness after drying was 25 μm. Thereafter, the sheet was dried at 100 ℃ for 3 minutes by a hot air dryer to remove the solvent, thereby forming a pressure-sensitive adhesive sheet.

A second release sheet (a light release Film, a Teijin Dupont Film) which had been subjected to a release treatment and had a higher peel strength than the first release sheet was laminated on one side of the pressure-sensitive adhesive sheet, to obtain the pressure-sensitive adhesive sheet of example 11 as a pressure-sensitive adhesive sheet with a release sheet.

(example 12)

An adhesive composition and a release sheet-equipped adhesive sheet were obtained in the same manner as in example 11, except that the amount of the colorant added was changed to 0.22 parts by mass.

(example 13)

An adhesive composition and a pressure-sensitive adhesive sheet with a release sheet were obtained in the same manner as in example 11, except that the colorant was changed to 0.1 part by mass of carbon BLACK (polylac a 903BLACK, manufactured by toyoyo color co., ltd.).

(example 14)

To 100 parts by mass of the acrylic polymer B2, 0.5 part by mass of an isocyanate-based crosslinking agent (Coronate L-55E, manufactured by tokyo co., LTD.), 2 parts by mass of a triazine-based ultraviolet absorber (Tinuvin477, manufactured by BASF JAPAN LTD.) as an ultraviolet absorber, and 0.2 part by mass of a copper, iron, manganese-based oxide-based pigment (TM BLACK 3550, manufactured by daidz), as a coloring agent, were added, and ethyl acetate as a solvent was added so that the solid content concentration became 35 mass%, to obtain an adhesive composition.

(example 15)

To 100 parts by mass of the acrylic polymer C2, 0.5 part by mass of an isocyanate-based crosslinking agent (Coronate L-55E, manufactured by tokyo co., LTD.), 2 parts by mass of a triazine-based ultraviolet absorber (Tinuvin477, manufactured by BASF JAPAN LTD.) as an ultraviolet absorber, and 0.16 part by mass of a copper, iron, and manganese-based oxide-based pigment (TM BLACK 3550, manufactured by daidz corporation) as a coloring agent were added, and ethyl acetate as a solvent was added so that the solid content concentration became 35% by mass, to obtain an adhesive composition.

Comparative example 11

An adhesive composition and a release sheet-equipped adhesive sheet were obtained in the same manner as in example 11, except that no colorant was added.

(example 16)

An adhesive composition and a release sheet-equipped adhesive sheet were obtained in the same manner as in example 11, except that the ultraviolet absorber was not added and the amount of the colorant added was changed to 0.14 parts by mass.

(evaluation)

< optical characteristics >

A light release separator as a second release sheet was peeled off, and a PET film (Cosmoshine a4300#100, manufactured by toyobo) was bonded to the second release sheet using a hand roller instead of the peeled separator to prepare a laminated film. The laminated film was cut into a size of 50mm in width and 50mm in length, and the first release sheet was peeled off. Next, the exposed adhesive surface was attached to a slide glass (manufactured by sonlang nitre, S9112) using a hand roller. The glass plate was closely adhered to the autoclave in this state at 40 ℃ under 5 atmospheres for 30 minutes.

The total light transmittance and haze of the obtained laminate were measured in accordance with JIS K7150 using an integrating sphere type light transmittance measuring apparatus (NDH-5000, manufactured by Nippon Denshoku industries Co., Ltd.). The measurement was performed 3 times, and the average value was defined as a measurement value.

< gel fraction >

The adhesive sheet was cut into pieces of 100mm × 60mm to prepare samples for measurement. About 0.1g of the adhesive sheet for measurement was taken out from a sample bottle, and 30ml of ethyl acetate was added thereto and shaken for 24 hours. Thereafter, the content of the sample bottle was separated by filtration through a 150-mesh stainless steel wire mesh, and the residue on the wire mesh was dried at 100 ℃ for 1 hour to measure the dry mass (g). The gel fraction was determined from the obtained dry mass according to the following formula 1.

Gel fraction (% by mass) × 100 (dry mass/collected mass of adhesive sheet) × 100 formula 1

Design

Samples were prepared in the same manner as in the optical property measurement, and placed on a display showing a black screen for evaluation.

O: looks darker than when nothing is left

X: without change

< visibility >

Samples were prepared in the same manner as in the measurement of optical properties, and placed on a display on which characters were displayed, and evaluated.

O: no feathering or blurring was observed

And (delta): feathering and blurring were observed

X: feathering and blurring were observed and the characters could not be interpreted

< decolorization >

A sample was prepared in the same manner as in the measurement of optical properties, and placed at 85 ℃ under an atmosphere of 85% relative humidity, and the total light transmittance after 240 hours was measured. The amount of change was calculated by the following formula based on the total light transmittance of the sample before being left at 85 ℃ and 85% relative humidity, and evaluated by the following evaluation criteria.

Change (%) - (total light transmittance of sample before treatment) - (total light transmittance of sample after treatment)

O: the variation of the total light transmittance is less than +/-10 percent, and the total light transmittance after treatment is less than 85 percent

And (delta): the variation of the total light transmittance is more than 10 percent, and the total light transmittance after treatment is less than 85 percent

X: the variation of the total light transmittance is more than 10%, and the total light transmittance after treatment is more than 85%

< UV cut-off >

The adhesive sheet with the transparent film as a base material was cut into 50mm × 50mm, and the separator was peeled off and attached to a glass slide (manufactured by Sonlang Nitri, S9112). After the glass plate was closely adhered to the autoclave maintained at 40 ℃ under 5 atmospheres for 30 minutes, the heavy-release separator was peeled off, and the spectral transmittance at a wavelength of 380nm was measured by an automatic recording spectrophotometer (model: UV-3100PC, Shimadzu corporation) and evaluated according to the following evaluation criteria.

O: the spectral transmittance at 380nm is less than 10%

X: a spectral transmittance at a wavelength of 380nm of 10% or more

[ Table 2]

MO: metal oxides

CB: carbon black

Adhesive sheets of examples 21 to 29 and comparative example 21 were produced and evaluated by the following methods.

< Synthesis of acrylic Polymer A3 >

Acrylic polymer a3 was made by solution polymerization in ethyl acetate. Butyl Acrylate (BA) and 2-hydroxyethyl acrylate (2HEA) are mixed according to the mass ratio of 70: 30, and AIBN (azobisisobutyronitrile) as a radical polymerization initiator was dissolved in the solution. The solution was heated to 60 ℃ to carry out random copolymerization to obtain an acrylic polymer A3. A35 mass% solution of the acrylic polymer A3 had a solution viscosity of 6,400 mPas at 23 ℃. Further, the acid value of the acrylic polymer A3 was 0.0 mgKOH/g.

< Synthesis of acrylic Polymer B3 >

The acrylic polymer B3 was made by solution polymerization in ethyl acetate. Mixing a 2-methoxyethyl acrylate Monomer (MEA), a 2-hydroxyethyl acrylate monomer (2HEA), Methyl Methacrylate (MMA), Dimethylacrylamide (DMAA) and Butyl Acrylate (BA) according to a mass ratio of 70: 10: 10: 5: 5, and dissolving AIBN (azobisisobutyronitrile) as a radical polymerization initiator in the solution. The solution was heated to 60 ℃ to carry out random copolymerization to obtain an acrylic polymer B3. A35% by mass solution of this acrylic polymer B3 had a solution viscosity of 2,000 mPas at 23 ℃. The acid value of the acrylic polymer B3 was 0.0 mgKOH/g.

< Synthesis of acrylic Polymer C3 >

The acrylic polymer C3 was made by solution polymerization in ethyl acetate. Butyl Acrylate (BA), Methyl Acrylate (MA), Methyl Methacrylate (MMA) and acrylic acid were added in a mass ratio of 87: 1: 4: 8, and dissolving AIBN (azobisisobutyronitrile) as a radical polymerization initiator in the solution. The solution was heated to 60 ℃ to carry out random copolymerization to obtain an acrylic polymer C3. A35 mass% solution of the acrylic polymer C3 had a solution viscosity of 4,200 mPas at 23 ℃. The acid value of the acrylic polymer C3 was 60.0 mgKOH/g.

(example 21)

An acrylic polymer A3, an ethyl acetate solution of a tolylene diisocyanate adduct of trimethylolpropane (CoronateL-55E, manufactured by tokyo co., ltd.), a copper, iron, manganese oxide-based pigment (TM BLACK 3550, manufactured by daidz chemical corporation), and ethyl acetate as a solvent were mixed to obtain a pressure-sensitive adhesive composition containing 0.5 parts by mass of a crosslinking agent, 0.15 parts by mass of a coloring agent, and a solid content concentration of 30% by mass per 100 parts by mass of the acrylic polymer A3.

The above adhesive composition was applied to a first release sheet (a heavy-duty release Film, a polyethylene terephthalate Film produced by Teijin Dupont Film co., ltd.) subjected to a release treatment). The coating was carried out using a Doctor Blade YD model manufactured by Gekko Seiko K.K. so that the thickness after drying was 100 μm. Thereafter, the sheet was dried at 100 ℃ for 3 minutes by a hot air dryer to remove the solvent, thereby forming a pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer.

A second release sheet (a light release Film, a Teijin Dupont Film) which had been subjected to a release treatment and had a higher peel strength than the first release sheet was attached to one side of the pressure-sensitive adhesive sheet, to obtain the pressure-sensitive adhesive sheet of example 21 as a pressure-sensitive adhesive sheet with a release sheet.

(example 22)

An adhesive composition and a release sheet-equipped adhesive sheet were obtained in the same manner as in example 21, except that the amount of the pigment to be added was changed so that the content of the colorant was 0.20 parts by mass.

(example 23)

An adhesive composition and a release sheet-equipped adhesive sheet were obtained in the same manner as in example 21, except that the amount of the pigment to be added was changed so that the content of the colorant was 0.06 parts by mass.

(example 24)

An adhesive composition and a release sheet-equipped adhesive sheet were obtained in the same manner as in example 21, except that the amount of the pigment to be added was changed so that the content of the colorant was 0.53 parts by mass.

(example 25)

An acrylic polymer C3, N' -tetraglycidyl-1, 3-benzenebis (methylamine) (mitsubishi gas chemical corporation, tetra-X), a copper, iron, manganese oxide pigment (daidz chemical corporation, TM BLACK 3550), and ethyl acetate as a solvent were mixed to obtain a binder composition containing 0.05 parts by mass of a crosslinking agent and 0.68 parts by mass of a colorant per 100 parts by mass of the acrylic polymer C3, and having a solid content concentration of 30% by mass. A release sheet-equipped pressure-sensitive adhesive sheet was obtained in the same manner as in example 21, except that the pressure-sensitive adhesive composition thus obtained was coated so that the thickness after drying became 25 μm.

Comparative example 21

An adhesive composition containing 0.05 parts by mass of a crosslinking agent per 100 parts by mass of the acrylic polymer B3 and having a solid content concentration of 30% by mass was obtained by mixing the acrylic polymer B3, N' -tetraglycidyl-1, 3-benzenebis (methylamine) (manufactured by mitsubishi gas chemical corporation, tetra d-X), and ethyl acetate as a solvent. A release sheet-equipped pressure-sensitive adhesive sheet was obtained in the same manner as in example 21, except that the pressure-sensitive adhesive composition thus obtained was coated so that the thickness after drying became 25 μm.

(example 26)

An adhesive composition and a pressure-sensitive adhesive sheet with a release sheet were obtained in the same manner as in example 25, except that carbon BLACK (multi lac a 903BLACK, manufactured by toyoyo color co., ltd.) was used as a colorant and the amount of the pigment to be added was changed so that the content was 1.7 parts by mass.

(example 27)

An adhesive composition and a pressure-sensitive adhesive sheet with a release sheet were obtained in the same manner as in example 25, except that carbon BLACK (multi lac a 903BLACK, manufactured by toyoyo color co., ltd.) was used as a colorant and the amount of the pigment to be added was changed so that the content was 2.8 parts by mass.

(example 28)

An adhesive composition and a pressure-sensitive adhesive sheet with a release sheet were obtained in the same manner as in comparative example 21, except that carbon black (NX-595 black, manufactured by daikon chemical industries) was used as a coloring agent and the amount of the pigment to be blended was changed so that the content thereof was 0.6 parts by mass.

(example 29)

An adhesive composition and a release sheet-equipped adhesive sheet were obtained in the same manner as in example 28, except that the amount of the pigment to be added was changed so that the content of the colorant was 1.2 parts by mass.

(evaluation)

< optical characteristics >

A light release separator as a second release sheet was peeled off, and a PET film (Cosmoshine a4300#100, manufactured by toyobo) was bonded to the second release sheet using a hand roller instead of the peeled separator to prepare a laminated film. The laminated film was cut into a size of 50mm in width and 50mm in length, and the first release sheet was peeled off. Next, the exposed adhesive surface was attached to a slide glass (manufactured by sonlang nitre, S9112) using a hand roller. The glass plate was closely adhered to the autoclave in this state at 40 ℃ under 5 atmospheres for 30 minutes.

The total light transmittance and haze of the obtained laminate were measured in accordance with JIS K7150 using an integrating sphere type light transmittance measuring apparatus (NDH-5000, manufactured by Nippon Denshoku industries Co., Ltd.). The measurement was performed 3 times, and the average value was defined as a measurement value.

< gel fraction >

About 0.1g of the adhesive sheet of each measurement sample was taken in a sample bottle, and 30ml of ethyl acetate was added thereto and shaken for 24 hours. Thereafter, the content of the sample bottle was separated by filtration through a 150-mesh stainless steel wire mesh, and the residue on the wire mesh was dried at 100 ℃ for 1 hour to measure the dry mass (g). The gel fraction was determined from the obtained dry mass according to the following formula 1.

Gel fraction (%) (dry mass/collected mass of adhesive sheet) × 100 · formula 1

Design

Samples were prepared in the same manner as in the optical property measurement, and placed on a display showing a black screen for evaluation.

O: looks darker than when nothing is left

X: without change

< visibility >

A sample was prepared in the same manner as in the optical property measurement, and the luminance of a display on which characters were displayed was adjusted to 500nit, and evaluated according to the following criteria. In practice, the visibility is preferably evaluated as o.

O: no feathering or blurring was observed

And (delta): blurring was observed, but the characters could be interpreted

X: feathering and blurring were observed and the characters could not be interpreted

< resistance to discoloration >

A sample was prepared in the same manner as in the measurement of optical properties, and placed at 85 ℃ under an atmosphere of 85% relative humidity, and the total light transmittance after 240 hours was measured. The amount of change was calculated by the following formula based on the total light transmittance of the sample before being left at 85 ℃ and 85% relative humidity, and evaluated by the following evaluation criteria.

Change (%) - (total light transmittance of sample before treatment) - (total light transmittance of sample after treatment)

O: the variation of the total light transmittance is less than +/-10 percent, and the total light transmittance after treatment is less than 85 percent

And (delta): the variation of the total light transmittance is more than 10 percent, and the total light transmittance after treatment is less than 85 percent

X: the variation of the total light transmittance is more than 10%, and the total light transmittance after treatment is more than 85%

[ Table 3]

[ Table 4]

The pressure-sensitive adhesive sheets obtained in the examples exhibited excellent design.

MO: metal oxides

CB: carbon black

Laminates of examples 101 to 106 and comparative example 101 were produced and evaluated by the following method.

< Synthesis of acrylic Polymer A4 >

Acrylic polymer a4 was made by solution polymerization in ethyl acetate. Butyl Acrylate (BA) and 2-hydroxyethyl acrylate (2HEA) are mixed according to the mass ratio of 70: 30, and AIBN (azobisisobutyronitrile) as a radical polymerization initiator was dissolved in the solution. The solution was heated to 60 ℃ to carry out random copolymerization to obtain an acrylic polymer A4. A35 mass% solution of the acrylic polymer A4 had a solution viscosity of 6,400 mPas at 23 ℃. Further, the acid value of the acrylic polymer A4 was 0.2 mgKOH/g.

< Synthesis of acrylic Polymer B4 >

The acrylic polymer B4 was made by solution polymerization in ethyl acetate. Butyl Acrylate (BA), Methyl Acrylate (MA), Methyl Methacrylate (MMA) and acrylic acid were added in a mass ratio of 87: 1: 4: 8, and dissolving AIBN (azobisisobutyronitrile) as a radical polymerization initiator in the solution. The solution was heated to 60 ℃ to carry out random copolymerization to obtain an acrylic polymer B4. A35 mass% solution of this acrylic polymer B4 had a solution viscosity of 4,200 mPas at 23 ℃. The acid value of the acrylic polymer B4 was 60.0 mgKOH/g.

(example 101)

< adhesive layer >

An acrylic polymer a4, an ethyl acetate solution of a tolylene diisocyanate adduct of trimethylolpropane (CoronateL-55E, manufactured by tokyo co., LTD.), a copper, iron, manganese oxide-based pigment (TM BLACK 3550, manufactured by daidzein co., LTD.), an ultraviolet absorber (manufactured by BASF pan jaltd., Tinuvin477), and ethyl acetate as a solvent were mixed to obtain a binder composition containing 0.2 parts by mass of a crosslinking agent, 0.06 parts by mass of a colorant, 1 part by mass of an ultraviolet absorber, and a solid content concentration of 30% by mass, based on 100 parts by mass of the acrylic polymer a 4.

The above adhesive composition was applied to a first release sheet (a heavy-duty release Film, a polyethylene terephthalate Film produced by Teijin Dupont Film co., ltd.) subjected to a release treatment). The coating was carried out using a Doctor Blade YD model manufactured by Gekko Seiko K.K. so that the thickness after drying was 200 μm. Thereafter, the sheet was dried at 100 ℃ for 3 minutes by a hot air dryer to remove the solvent, thereby forming a pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer.

A second release sheet (a light release Film, a Teijin Dupont Film) which had been subjected to a release treatment and had a higher peel strength than the first release sheet was laminated on one side of the pressure-sensitive adhesive sheet to obtain a pressure-sensitive adhesive sheet with a release sheet.

< surface layer >

On the surface of a glass plate (120 mm in length. times.70 mm in width. times.0.7 mm in thickness), an ultraviolet-curable ink was screen-printed in a frame shape (inner edge size: 90mm in length. times.50 mm in width. times.5 mm) so that the coating thickness was 5 μm. Subsequently, the printed ultraviolet curable ink is cured by irradiation with ultraviolet light. This procedure was repeated 5 times to obtain a printed step glass plate having a step of 25 μm.

< layer containing conductive Member >

An ITO glass (glass 1004 with an ITO film, manufactured by Geomatec corporation) in which one surface of a glass plate (120 mm in the vertical direction, 70mm in the horizontal direction, 0.7mm in thickness) was subjected to ITO treatment was used, and 5 pieces of the ITO glass were etched in the vertical direction and 5 pieces of the ITO glass were etched in the horizontal direction at intervals of 2mm and 8mm in width to prepare etched ITO glass.

< production of laminate >

The first release sheet of the release-sheet-attached pressure-sensitive adhesive sheet cut into 90mm × 54mm was peeled off, and the exposed pressure-sensitive adhesive surface was bonded to the entire printed surface on the frame edge of the glass plate (surface layer) having a print level difference by using a hand roller. Thereafter, the second release sheet of the pressure-sensitive adhesive sheet with a release sheet was peeled off, and the etched ITO glass was bonded to the exposed adhesive surface using a laminator (IKO-650 EMT, product of YOUBON corporation), and the bonded surfaces were closely bonded by holding the pressure-sensitive adhesive sheet in an autoclave at 40 ℃ and 5 atmospheres for 30 minutes. Thus, a laminate of example 101 was obtained.

(example 102)

An acrylic polymer a4, an ethyl acetate solution of a tolylene diisocyanate adduct of trimethylolpropane (CoronateL-55E, manufactured by tokyo corporation), carbon BLACK (polylac a 903BLACK, manufactured by toshiba corporation), an ultraviolet absorber (Tinuvin477, manufactured by basf corporation), and ethyl acetate as a solvent were mixed to obtain an adhesive composition containing 0.2 parts by mass of a crosslinking agent, 0.10 parts by mass of a colorant, and 1 part by mass of an ultraviolet absorber per 100 parts by mass of the acrylic polymer a4, and having a solid content concentration of 30% by mass.

A release sheet-equipped adhesive sheet and a laminate were obtained in the same manner as in example 101, except that the adhesive composition was coated so that the thickness after drying became 100 μm.

(example 103)

An adhesive composition, a release sheet-attached adhesive sheet, and a laminate were obtained in the same manner as in example 102, except that the amount of carbon black added was changed so that the content of the colorant was 0.23 parts by mass.

(example 104)

< adhesive layer >

An adhesive composition containing 100 parts by mass of acrylic polymer B4, 0.1 part by mass of a crosslinking agent, 0.42 part by mass of a colorant, and 1 part by mass of an ultraviolet absorber, and having a solid content concentration of 30% by mass, was obtained by mixing acrylic polymer B4, N' -tetraglycidyl-1, 3-benzenebis (methylamine) (mitrad-X, manufactured by mitsubishi gas chemical corporation), carbon BLACK (Multilac a 903BLACK, manufactured by toyoyo color corporation), an ultraviolet absorber (Tinuvin477, manufactured by basf corporation), and ethyl acetate as a solvent. A release sheet-equipped adhesive sheet was obtained in the same manner as in example 101, except that the adhesive composition thus obtained was coated so that the thickness after drying became 50 μm.

< surface layer >

An ultraviolet curable ink was screen-printed on the surface of a polycarbonate sheet (manufactured by Mitsubishi gas chemical company, IUPILON MR58, hard coat side, length 120 mm. times. width 70 mm. times. thickness 1mm) in a frame shape (inner edge size: length 90 mm. times. width 50 mm. times. width 5mm) so that the coating thickness was 5 μm. Subsequently, the printed ultraviolet curable ink is cured by irradiation with ultraviolet light. This step was repeated 2 times to obtain a printed step resin plate having a step of 10 μm.

< layer containing conductive Member >

A layer including a conductive member was produced in the same manner as in example 101.

< production of laminate >

A laminate was obtained in the same manner as in example 101, except that the pressure-sensitive adhesive sheet with a release sheet and the surface layer were changed to the pressure-sensitive adhesive sheet with a release sheet and the surface layer obtained above.

(example 105)

An adhesive composition, a release sheet-attached adhesive sheet, and a laminate were obtained in the same manner as in example 101, except that a printed step resin plate was used as the surface layer.

(example 106)

An adhesive composition, a pressure-sensitive adhesive sheet with a release sheet, and a laminate were obtained in the same manner as in example 104, except that 0.06 part by mass of a copper, iron, or manganese oxide pigment (TM BLACK 3550, manufactured by daidz chemical) was used as a colorant and the thickness of the pressure-sensitive adhesive sheet was set to 200 μm.

Comparative example 101

An adhesive composition, a release sheet-attached adhesive sheet, and a laminate were obtained in the same manner as in example 102, except that the colorant was removed.

(evaluation)

< optical characteristics >

In the pressure-sensitive adhesive sheet with a release sheet, a light release separator as a second release sheet was peeled off, and a PET film (Cosmoshine a4300#100, manufactured by tokyo corporation) was bonded to a hand-held roller in place of the peeled separator to prepare a laminated film. The laminated film was cut into a size of 50mm in width and 50mm in length, and the first release sheet was peeled off. Next, the exposed adhesive surface was attached to a slide glass (manufactured by sonlang nitre, S9112) using a hand roller. The glass plate was closely adhered to the autoclave in this state at 40 ℃ under 5 atmospheres for 30 minutes.

The total light transmittance and haze of the obtained laminate were measured in accordance with JIS K7150 using an integrating sphere type light transmittance measuring apparatus (NDH-5000, manufactured by Nippon Denshoku industries Co., Ltd.). The measurement was performed 3 times, and the average value was defined as a measurement value.

< gel fraction >

About 0.1g of the adhesive layer of the pressure-sensitive adhesive sheet with a release sheet was collected in a sample bottle, and 30ml of ethyl acetate was added thereto and shaken for 24 hours. Thereafter, the content of the sample bottle was separated by filtration through a 150-mesh stainless steel wire mesh, and the residue on the wire mesh was dried at 100 ℃ for 1 hour to measure the dry mass (g). The gel fraction was determined from the obtained dry mass according to the following formula 1.

Gel fraction (%) (dry mass/collected mass of adhesive layer) × 100 · equation 1

Design

The laminates obtained in examples and comparative examples were visually observed from the surface layer side, and the case where the central portion and the printed step portion had an integral feeling was evaluated as o, and the case where no integral feeling was evaluated as x.

< ultraviolet absorption Capacity >

The pressure-sensitive adhesive sheet with the release sheet was cut into 50mm × 50 mm. The light release spacer as a second release sheet was peeled off and attached to a glass slide (manufactured by Song Lang Nitro jus, S9112). After the sheet was held in an autoclave at 40 ℃ under 5 atmospheres for 30 minutes and adhered to a glass plate, a heavy release separator as a first release sheet was peeled off, and the spectral transmittance at a wavelength of 380nm was measured using an automatic recording spectrophotometer (model: UV-3100PC, manufactured by Shimadzu corporation) and evaluated according to the following evaluation criteria.

O: the spectral transmittance at 380nm is less than 10%

X: a spectral transmittance at a wavelength of 380nm of 10% or more

< perspective >

The laminates obtained in examples and comparative examples were observed by visual observation from the surface layer side, and the case where no etching streaks were observed was evaluated as "o", and the case where etching streaks were observed was evaluated as "x".

[ Table 5]

MO: metal oxide (copper, iron, manganese oxide-based pigment)

CB: carbon black

In the embodiment, the design of the laminate is high, and the perspective of the layer including the conductive member in the laminate is suppressed.

Description of the reference numerals

1 pressure-sensitive adhesive sheet with Release sheet

11 pressure-sensitive adhesive sheet

12a Release sheet

12b Release sheet

10 laminated body

13 surface layer

14 adhesive layer

16 layer containing conductive member

Claims (23)

1. A pressure-sensitive adhesive sheet for bonding a transparent member, comprising an acrylic polymer and a colorant. 2 . The adhesive sheet for bonding a transparent member according to claim 1 , wherein the product of the total light transmittance and the haze value is 170 or less. 3 . 3 . The pressure-sensitive adhesive sheet for laminating a transparent member according to claim 1 , wherein the colorant contains at least one selected from the group consisting of metal oxides and carbon black. 4 . 4 . The pressure-sensitive adhesive sheet for bonding a transparent member according to claim 1 , wherein the colorant is a metal oxide. 5 . 5 . The pressure-sensitive adhesive sheet for bonding a transparent member according to claim 1 , wherein the acid value of the acrylic polymer is 50 mgKOH/g or less. 6 . 6 . The adhesive sheet for bonding a transparent member according to claim 1 , wherein the total light transmittance is 5 to 90%. 7 . 7 . The pressure-sensitive adhesive sheet for bonding a transparent member according to claim 1 , wherein the haze is 0.1 to 15%. 8 . 8 . The pressure-sensitive adhesive sheet for bonding a transparent member according to claim 1 , wherein the colorant has a primary average particle diameter of 0.01 to 15 μm. 9 . 9 . The pressure-sensitive adhesive sheet for transparent member bonding according to claim 1 , wherein the pressure-sensitive adhesive sheet for transparent member bonding further contains an ultraviolet absorber. 10 . 10 . The adhesive sheet for laminating a transparent member according to claim 9 , wherein the ultraviolet absorber is represented by the following general formula (1) or (2), 11 . [hua 1] General formula (1)

In the general formula (1), R ¹ represents a hydrogen atom, a halogen atom, an alkoxy group having 1 to 4 carbon atoms, a nitro group or a cyano group, and R ² represents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms, R ³ represents an alkyl system structure, [hua 2] General formula (2)

In the general formula (2), R ⁴ , R ⁵ and R ⁶ are hydrogen atoms, hydroxyl groups, alkyl-based structures or halogen atoms, and not all of R ⁴ , R ⁵ and R ⁶ are hydrogen atoms. The pressure-sensitive adhesive sheet for transparent member bonding according to any one of claims 1 to 8, wherein the pressure-sensitive adhesive sheet for transparent member bonding further contains a photopolymerization initiator and an acrylic monomer, and is a semi-polymeric cured state. The pressure-sensitive adhesive sheet for bonding a transparent member according to any one of claims 1 to 11, which has a thickness of 1 to 5000 μm. The said transparent member is an optical member, The adhesive sheet for transparent member bonding in any one of Claims 1-12. 14. A method for producing a laminate comprising a step of post-curing the PSA sheet by irradiating an active energy ray after bonding the PSA sheet according to claim 11 to an adherend in a semi-cured state . 15. A laminate comprising a surface layer, an adhesive layer, and a layer containing a conductive member in this order, wherein The adhesive layer includes an acrylic polymer and a colorant. 16. The laminate according to claim 15, wherein the surface layer is a glass layer or a resin layer. 17. The laminate according to claim 15 or 16, wherein the layer including the conductive member is a touch sensor. 18 . The laminate according to claim 15 , wherein the colorant is a black colorant. 19 . 19 . The laminate according to claim 15 , wherein the colorant is a black pigment. 20 . 20 . The laminate according to claim 15 , wherein the colorant contains at least one selected from metal oxides and carbon black. 21 . 21 . The laminate according to claim 15 , wherein the total light transmittance of the pressure-sensitive adhesive layer is 5 to 90%. 22 . 22 . The laminate according to claim 15 , wherein the pressure-sensitive adhesive layer has a haze of 0.1 to 15%. 23 . 23 . The laminate according to claim 15 , wherein the colorant is a black pigment, and the primary average particle diameter of the black pigment is 0.01 μm or more and less than 5 μm. 24 .

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