CN114207067A

CN114207067A - Adhesive sheet for bonding, multilayer body, and method for producing multilayer body

Info

Publication number: CN114207067A
Application number: CN202080056449.3A
Authority: CN
Inventors: 武田圣英; 冨田惠介
Original assignee: Mitsubishi Gas Chemical Co Inc
Current assignee: Mitsubishi Gas Chemical Co Inc
Priority date: 2019-08-09
Filing date: 2020-08-04
Publication date: 2022-03-18
Also published as: JPWO2021029283A1; CN117165196A; WO2021029283A1; JP7533463B2

Abstract

The invention provides an adhesive sheet for bonding which can cope with high temperature treatment, a multilayer body using the adhesive sheet, and a method for manufacturing the multilayer body. The adhesive sheet for bonding comprises a substrate containing a polycarbonate and an adhesive layer provided on the substrate, wherein the glass transition temperature of the substrate as measured by differential scanning calorimetry is 160 ℃ or higher.

Description

Adhesive sheet for bonding, multilayer body, and method for producing multilayer body

Technical Field

The present invention relates to an adhesive sheet for bonding, a multilayer body, and a method for producing a multilayer body. In particular, the present invention relates to an adhesive sheet for bonding using a polycarbonate-containing substrate.

Background

Conventionally, as a substrate for an adhesive sheet, a substrate using polyolefin such as polypropylene or polyethylene has been known. However, polyolefin sheets have a problem in heat resistance. On the other hand, polyethylene terephthalate may be considered for improving heat resistance. However, polyethylene terephthalate is required to be improved in view of moisture-humidity property and moldability. Therefore, the use of polycarbonate as a base material for an adhesive sheet has been studied.

For example, patent document 1 discloses a laminate including an adhesive sheet, wherein a front panel has a B layer containing a polycarbonate resin as a main component resin and an a layer containing a thermoplastic resin different from the polycarbonate resin as a main component resin, the total thickness of the a layers is 10 to 250 μm, the ratio ((a)/(T)) of the thickness (a) of the a layer 1 to the total thickness (T) of the a layer and the B layer is 0.05 to 0.40, and the internal stress (σ) of the front panel and the adhesive sheet is 0.47MPa or less when the laminate of the front panel and the adhesive sheet is exposed to a temperature 85 ℃ and humidity 85% RH environment for 120 hours.

Patent document 2 discloses an adhesive sheet in which when the 180 ° adhesive force to glass at 23 ℃ is represented by P and the 180 ° adhesive force to glass at 80 ℃ is represented by Q, the value represented by Q/P is 1 or more. Also disclosed is a laminate comprising the adhesive sheet and a polycarbonate substrate located on at least one surface of the adhesive sheet.

Documents of the prior art

Patent document

Patent document 1: international publication No. 2016/158827

Patent document 2: japanese patent laid-open publication No. 2017-200975

Disclosure of Invention

Technical problem to be solved by the invention

As described above, an adhesive sheet comprising a substrate containing polycarbonate and an adhesive layer provided on the substrate has been studied. In recent years, however, the demand for adhesive sheets has been increasing, and it is desired to provide newer materials. In particular, recently, there is an increasing demand for an adhesive sheet for bonding having excellent heat resistance that can cope with high-temperature processing.

The present invention has been made to solve the above-described problems, and an object of the present invention is to provide an adhesive sheet for bonding that can cope with high-temperature processing, and a multilayer body and a method for producing a multilayer body using the adhesive sheet, the adhesive sheet including a substrate containing polycarbonate and an adhesive layer provided on the substrate.

Technical solution for solving technical problem

The present inventors have studied based on the above-mentioned problems, and as a result, have found that the above-mentioned problems can be solved by adjusting the glass transition temperature of the substrate to 160 ℃ or higher. Specifically, the technical problems are solved by the following technical means.

< 1 > an adhesive sheet for bonding, comprising:

a substrate comprising polycarbonate; and

an adhesive layer disposed on the base material,

the glass transition temperature of the substrate is 160 ℃ or higher as measured by differential scanning calorimetry.

< 2 > the adhesive sheet for bonding of < 1 >, wherein the polycarbonate contained in the substrate comprises 100 to 10 mass% of bisphenol AP type polycarbonate and 0 to 90 mass% of bisphenol A type polycarbonate, and wherein the total mass of bisphenol AP type polycarbonate and bisphenol A type polycarbonate is not more than 100 mass%.

The adhesive sheet for bonding of < 3 > such as < 1 > or < 2 >, wherein the base material contains 10 to 90 parts by mass of polyarylate per 100 parts by mass of the resin component contained in the base material.

The adhesive sheet for bonding of any one of < 4 > to < 1 > -3 >, wherein the glass transition temperature of the substrate as measured by differential scanning calorimetry is 200 ℃ or lower.

The adhesive sheet for bonding of any one of < 5 > to < 1 > -4 >, wherein the adhesive layer contains an acrylic adhesive.

The adhesive sheet for bonding of any one of < 6 > to < 1 > -5 > wherein the adhesive layer contains a silicone adhesive.

The adhesive sheet for bonding of < 7 > as defined in any one of < 1 > to < 6 >, wherein the adhesive layer contains a polyurethane adhesive.

The adhesive sheet for bonding of any one of < 8 > to < 1 > -7 > wherein the substrate has an in-plane retardation Re of 100nm or less.

The adhesive sheet for bonding of any one of < 9 > to < 1 > -8 > wherein the substrate has a haze of 1.5% or less.

The adhesive sheet for bonding of any one of < 10 > to < 1 > -9 > wherein the thickness of the substrate is from 30 μm to 200 μm.

The adhesive sheet for bonding of any one of < 11 > to < 1 > -10 > wherein the adhesive layer has a thickness of 10 μm or more and 70 μm or less.

< 12 > the adhesive sheet for bonding of any one of < 1 > to < 11 >, wherein the sheet is laminated on a polycarbonate mirror surface film on the adhesive layer side, and the sheet is peeled under a condition of 152 mm/min in a direction of 180 ° according to JIS Z0237, and wherein the peel force is 0.001 to 3N/25 mm.

The adhesive sheet for bonding of any one of < 13 > to < 1 > -12 > wherein a primer layer is provided between the substrate and the adhesive layer.

< 14 > a multilayer body, wherein the adhesive layer side of the adhesive sheet for bonding according to any one of < 1 > - < 13 > is bonded to at least a part of the surface of a resin molded body.

< 15 > the multilayer body according to < 14 >, wherein the resin molded body is a resin sheet.

A multilayer body of < 16 > such as < 14 > or < 15 >, wherein the resin molded body contains polycarbonate.

A multilayer body of < 17 > such as < 14 > or < 15 > wherein the resin molded body contains polyimide.

< 18 > a method for producing a multilayer body, comprising the step of attaching the adhesive sheet for bonding of any one of < 1 > to < 13 > to a resin molded body.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present invention, there are provided an adhesive sheet for bonding that can cope with high-temperature processing, and a multilayer body and a method for producing a multilayer body using the adhesive sheet.

Drawings

Fig. 1 is a schematic view showing an example of the layer structure of the bonding adhesive sheet of the present invention.

Detailed Description

The present invention will be described in detail below. In the present specification, "to" is used to include numerical values described before and after the "to" as a lower limit value and an upper limit value.

In the present specification, unless otherwise specified, various physical property values and characteristic values indicate values at 23 ℃.

In the present specification, "sheet" refers to an article which is thin and whose thickness is small with respect to the length and width and is flat, including "film". Also, the "sheet" in the present specification may be a single layer or a plurality of layers.

In the present specification, the term (meth) acrylate may include both acrylates and methacrylates.

[ adhesive sheet for bonding ]

The adhesive sheet for bonding (hereinafter, may be referred to as "sheet" or "adhesive sheet") of the present invention is characterized by comprising a substrate containing polycarbonate and an adhesive layer provided on the substrate, and the substrate has a glass transition temperature of 160 ℃ or higher as measured by differential scanning calorimetry. With this configuration, it is possible to provide an adhesive sheet for bonding that can cope with high-temperature processing. Further, the adhesive sheet for bonding is excellent in both of the adhesiveness to other members (for example, a resin molded article described later) and the removability, and is excellent in transparency. The adhesive sheet for bonding obtained by providing the adhesive layer on the substrate having a glass transition temperature of 160 ℃ or higher can be used as a protective film for a product requiring high-temperature treatment or a product requiring reliability test such as high-temperature treatment in inspection.

The adhesive sheet of the present invention has an adhesive layer provided on a base material as an essential component. As a preferred embodiment of the present invention, as shown in fig. 1, an adhesive sheet having an adhesive layer 12, a primer layer 16 and a substrate 20 can be exemplified as the adhesive sheet 10 of the present invention.

In the present invention, the adhesive layer 12, the primer layer 16, and the substrate 20 may be 1 layer or 2 or more layers.

In a preferred embodiment of the present invention, at least one of the adhesive layers included in the adhesive sheet of the present invention may be provided on the surface of the substrate, or an undercoat layer or another layer may be provided between the substrate and the adhesive layer. In the adhesive sheet of the present invention, the adhesive layer is preferably provided on the surface of the primer layer on the side opposite to the substrate side.

In a preferred embodiment of the present invention, the primer layer is generally disposed between the substrate and the adhesive layer. Impurities and the like from the polycarbonate contained in the substrate may enter the adhesive layer to lower the adhesiveness, deteriorate/decompose the substrate layer, or generate bubbles, but by having the undercoat layer, these phenomena can be effectively suppressed.

The primer layer is preferably disposed between the substrate and the adhesive layer, and more preferably disposed such that one surface of the primer layer is in contact with the surface of the substrate and the other surface is in contact with the surface of the adhesive layer. However, another layer may be provided between the primer layer and the substrate and/or between the primer layer and the adhesive layer.

Examples of the other layers in the adhesive sheet of the present invention include a hard coat layer, an ultraviolet absorbing layer, an antistatic layer, an antireflection layer, an adhesion-preventing layer, a refractive index matching (index matching) layer, a print coat layer, and a release layer.

The substrate, the adhesive layer, the primer layer, and the hard coat layer will be described in detail below.

< substrate >

In the adhesive sheet of the present invention, the base material contains polycarbonate, and the glass transition temperature of the base material as measured by differential scanning calorimetry is 160 ℃ or higher. When the glass transition temperature is not lower than the lower limit value, an adhesive sheet for bonding having excellent heat resistance can be obtained.

The glass transition temperature of the substrate is preferably 160 ℃ or higher, and more preferably 161 ℃ or higher. The glass transition temperature of the substrate is preferably 200 ℃ or lower, more preferably 190 ℃ or lower, and still more preferably 180 ℃ or lower. The glass transition temperature was measured by the method described in the examples described later (hereinafter, the same applies to the glass transition temperature).

Examples of means for adjusting the glass transition temperature of the substrate to the above range include selection of the type of polycarbonate to be used, addition of other resins, and the like. Specifically, it is possible to add polycarbonate having a high glass transition temperature such as bisphenol AP type polycarbonate, or to add another resin having a high glass transition temperature such as polyarylate. Details of these will be described later.

The substrate used in the present invention preferably has an in-plane retardation (Re) of 100nm or less, more preferably 80nm or less, still more preferably 60nm or less, yet more preferably 45nm or less, and still more preferably 40nm or less. By setting the upper limit value or less, not only application to liquid crystal parts but also shrinkage during high-temperature processing can be expected to be reduced. The lower limit is preferably as low as possible, but is actually 0.1nm or more.

The haze of the substrate is preferably 1.5% or less, more preferably 1.2% or less, and still more preferably 1.0% or less. The lower limit is not particularly limited, and is preferably 0%, but the performance requirements can be sufficiently satisfied even when the lower limit is 0.01% or more, and further 0.1% or more.

In the present specification, the haze is a value measured by a method described in examples described later.

The thickness of the base material is not particularly limited, but is preferably 30 μm or more, more preferably 35 μm or more, still more preferably 40 μm or more, and still more preferably 50 μm. When the lower limit value is not less than the above-described lower limit value, the material strength (tensile strength and the like) of the adhesive sheet tends to be further improved. The thickness of the substrate is preferably 200 μm or less, more preferably 150 μm or less, and may be 120 μm or less. By setting the upper limit value or less, it is possible to more effectively suppress the problem that the substrate is likely to be peeled off when the substrate is likely to be stuck due to the rigidity of the substrate.

Next, the material of the base material of the present invention will be explained.

The substrate used in the present invention contains polycarbonate.

The type of the polycarbonate contained in the substrate is not particularly limited as long as it contains a unit having a carbonate bond in the main molecular chain, [ O-R-OC (═ O) ] -, where R is a hydrocarbon group, specifically, a group having a linear structure or a branched structure including an aliphatic group, an aromatic group, or both an aliphatic group and an aromatic group, and is preferably an aromatic polycarbonate, and more preferably a polycarbonate having a bisphenol skeleton. By using such a polycarbonate, more excellent heat resistance and toughness can be achieved. The polycarbonate having a bisphenol skeleton preferably has 90 mol% or more of the total structural units as structural units having a bisphenol skeleton.

The viscosity average molecular weight (Mv) of the polycarbonate is preferably 10,000 or more, more preferably 12,000 or more, still more preferably 15,000 or more, and further preferably 20,000 or more. When the lower limit value is not less than the above-described lower limit value, the durability of the base material tends to be further improved. The upper limit of the viscosity average molecular weight (Mv) of the polycarbonate is preferably 45,000 or less, more preferably 40,000 or less, and still more preferably 34,000 or less. When the upper limit value is not more than the above-mentioned upper limit value, the moldability of the base material tends to be further improved.

The viscosity average molecular weight (Mv) means: the intrinsic viscosity [ eta ] at 25 ℃ was determined using methylene chloride as a solvent and an Ubbelohde viscometer](Unit dL/g), viscosity formula according to Schnell [. eta. ] -1.23X 10^－4×Mv^0.83The calculated value.

When 2 or more kinds of polycarbonates are used, the viscosity-average molecular weight of the mixture is assumed (hereinafter, the same applies to various physical properties).

The substrate used in the present invention may be composed of only polycarbonate, or may contain other resin components. As another resin, polyarylate can be exemplified.

The total amount of the resin components in the base material is preferably 90 mass% or more, more preferably 95 mass% or more, and may be 99 mass% or more of the whole. The resin component may contain only 1 kind of polycarbonate, or may contain 2 or more kinds. When a resin component other than polycarbonate (for example, polyarylate) is contained, the other resin component may contain only 1 kind, or may contain 2 or more kinds. Further, as components other than the resin component, additives described later can be cited.

The first embodiment of the substrate used in the present invention is a substrate in which the polycarbonate contains 100 to 10 mass% of bisphenol AP type polycarbonate and 0 to 90 mass% of bisphenol A type polycarbonate (wherein the total mass of bisphenol AP type polycarbonate and bisphenol A type polycarbonate does not exceed 100 mass%). In the first embodiment of the substrate, the polycarbonate preferably contains 20 to 90 mass% of bisphenol AP type polycarbonate and 10 to 80 mass% of bisphenol A type polycarbonate, and more preferably contains 30 to 80 mass% of bisphenol AP type polycarbonate and 20 to 70 mass% of bisphenol A type polycarbonate. In this way, not only is heat resistance excellent, but also in-plane retardation of the resulting sheet can be reduced.

In the present embodiment, the total amount of the polycarbonate relative to the substrate is preferably 90% by mass or more, more preferably 95% by mass or more, and still more preferably 98% by mass or more.

The bisphenol AP type polycarbonate and the bisphenol A type polycarbonate may contain only 1 type, or may contain 2 or more types, respectively.

Hereinafter, bisphenol AP type polycarbonate and bisphenol A type polycarbonate will be described in detail.

Bisphenol AP type polycarbonate

The bisphenol AP type polycarbonate is a resin having a carbonate unit derived from bisphenol AP and a derivative thereof, and preferably has a structural unit represented by the following formula (A-1). Wherein represents a binding site.

In the formula (A-1), R¹～R⁴Each independently represents a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, an alkyl group having 1 to 9 (preferably 1 to 3) carbon atoms, an aryl group having 6 to 12 (preferably 6 to 10) carbon atoms, an alkoxy group having 1 to 5 (preferably 1 to 3) carbon atoms, an alkenyl group having 2 to 5 (preferably 2 or 3) carbon atoms, or an aralkyl group having 7 to 17 (preferably 7 to 11) carbon atoms. l represents an integer of 0 to 5. m and n are each independently an integer of 0 to 4. Indicates the binding site.

The structural unit represented by the formula (A-1) is preferably a structural unit represented by the following formula (A-2). Wherein represents a binding site.

R¹、R²、R³、R⁴The meanings of l, m and n are the same as those of the formula (A-1).

The structural unit represented by the formula (A-2) is preferably a structural unit represented by the following formula (A-3). Wherein represents a binding site.

The content of the structural unit represented by the formula (A-1) in the bisphenol AP type polycarbonate is preferably 70 mol% or more, more preferably 80 mol% or more, and still more preferably 90 mol% or more of the total structural units. The upper limit is not particularly limited, and the structural unit represented by the formula (A-1) may be contained in 100 mol%. The structural unit derived from bisphenol AP may be only 1 type, or may be composed of 2 or more types. The bisphenol AP type polycarbonate is particularly preferably a resin comprising substantially the entire amount of the structural unit of the formula (A-1). The substantially total amount referred to herein specifically means 99.0 mol% or more, preferably 99.5 mol% or more, and more preferably 99.9 mol% or more.

The bisphenol AP type polycarbonate may have other structural units than carbonate units derived from bisphenol AP and derivatives thereof. As the dihydroxy compound constituting such another structural unit, for example, the aromatic dihydroxy compound described in paragraph 0014 of Japanese patent laid-open publication No. 2018-154819 can be cited, and these contents are incorporated into the present specification.

The method for producing the bisphenol AP polycarbonate is not particularly limited, and any method may be employed. Examples thereof include an interfacial polymerization method, a melt transesterification method, a pyridine method, a ring-opening polymerization method of a cyclic carbonate compound, a solid-phase transesterification method of a prepolymer, and the like.

In the present invention, the bisphenol AP type polycarbonate preferably has a viscosity average molecular weight of 10,000 to 28,000. The lower limit value is more preferably 11,000 or more, still more preferably 12,000 or more, and still more preferably 13,000 or more. The upper limit is more preferably 25,000 or less, still more preferably 23,000 or less, and still more preferably 20,500 or less. By setting the viscosity average molecular weight as described above, excellent heat resistance can be imparted while maintaining the transparency of the obtained base material and adhesive sheet. By using such a bisphenol AP type polycarbonate, the viscosity average molecular weight of the entire polycarbonate component can be easily brought within a desired range.

The glass transition temperature (Tg) of the bisphenol AP type polycarbonate is preferably 172 ℃ or higher, more preferably 175 ℃ or higher, and still more preferably 180 ℃ or higher. The upper limit is preferably 210 ℃ or lower, more preferably 200 ℃ or lower, and still more preferably 190 ℃ or lower. By using such a bisphenol AP type polycarbonate, the glass transition temperature of the entire polycarbonate component can be easily brought within a desired range.

Bisphenol A polycarbonate

The bisphenol a polycarbonate means a polycarbonate having a carbonate unit derived from bisphenol a and a derivative thereof.

The content of the carbonate unit derived from bisphenol a and a derivative thereof in the bisphenol a polycarbonate is preferably 70 mol% or more, more preferably 80 mol% or more, and still more preferably 90 mol% or more of the total structural units. The upper limit is not particularly limited, and may be 100 mol% of a carbonate unit derived from bisphenol A or a derivative thereof. The bisphenol a polycarbonate is particularly preferably a resin substantially containing the entire amount of carbonate units derived from bisphenol a and derivatives thereof. The substantially total amount referred to herein specifically means 99.0 mol% or more, preferably 99.5 mol% or more, and more preferably 99.9 mol% or more.

The bisphenol a polycarbonate may have other structural units than the carbonate units derived from bisphenol a and derivatives thereof. As the dihydroxy compound constituting such another structural unit, for example, an aromatic dihydroxy compound described in paragraph 0014 of Japanese patent laid-open publication No. 2018-154819 can be cited, and these contents are incorporated into the present specification.

The method for producing the bisphenol a polycarbonate is not particularly limited, and any method may be employed. Examples thereof include an interfacial polymerization method, a melt transesterification method, a pyridine method, a ring-opening polymerization method of a cyclic carbonate compound, a solid-phase transesterification method of a prepolymer, and the like.

In the present invention, the bisphenol A polycarbonate preferably has a viscosity average molecular weight of 10,000 to 45,000. The lower limit value is more preferably 10,200 or more, still more preferably 10,500 or more, and still more preferably 10,750 or more. When the lower limit value is not less than the above-described lower limit value, the durability of the base material tends to be improved. The upper limit is more preferably 43,000 or less, still more preferably 40,000 or less, and still more preferably 35,000 or less. When the upper limit value is not more than the above-mentioned upper limit value, the moldability tends to be improved.

A second embodiment of the base material used in the present invention is an embodiment in which 100 parts by mass of the resin component contained in the base material contains 10 to 90 parts by mass of polyarylate. In this manner, a base material exhibiting excellent yield strength can be obtained. In the second embodiment of the base material, it is preferable that the resin component contained in the base material contains 20 to 80 parts by mass of polyarylate per 100 parts by mass of the resin component contained in the base material, and it is more preferable that the resin component contained in the base material contains 25 to 75 parts by mass of polyarylate per 100 parts by mass of the resin component contained in the base material.

In the second embodiment of the substrate, the polycarbonate and the polyarylate may contain only 1 type, or 2 or more types, respectively.

In the second embodiment of the substrate, the total amount of the polycarbonate and the polyarylate in the substrate is preferably 90% by mass or more, more preferably 95% by mass or more, and still more preferably 98% by mass or more of the substrate.

Polycarbonates

In the second embodiment, the polycarbonate may be any polycarbonate, and preferably contains a bisphenol a polycarbonate. The meaning of the bisphenol a polycarbonate is the same as that of the bisphenol a polycarbonate described in the first embodiment of the substrate, and the preferable range is the same.

Polyarylates

The polyarylate used in the present invention is preferably an aromatic polyester composed of a structural unit derived from an aromatic dicarboxylic acid and a structural unit derived from a bisphenol.

Examples of the aromatic dicarboxylic acid include terephthalic acid, isophthalic acid, 1, 4-naphthalenedicarboxylic acid, 1, 5-naphthalenedicarboxylic acid, 2, 6-naphthalenedicarboxylic acid, benzophenonedicarboxylic acid, 4 ' -diphenyldicarboxylic acid, 3 ' -diphenyldicarboxylic acid, and 4,4 ' -diphenyletherdicarboxylic acid, and terephthalic acid and isophthalic acid are more preferable.

Examples of the bisphenol include 2, 2-bis (4-hydroxyphenyl) propane, 2-bis (4-hydroxy-3, 5-dimethylphenyl) propane, 2-bis (4-hydroxy-3, 5-dibromophenyl) propane, 2-bis (4-hydroxy-3, 5-dichlorophenyl) propane, 4 ' -dihydroxydiphenyl sulfone, 4 ' -dihydroxydiphenyl ether, 4 ' -dihydroxydiphenyl sulfide, 4 ' -dihydroxydiphenyl ketone, 4 ' -dihydroxydiphenyl methane, 1-bis (4-hydroxyphenyl) cyclohexane, 1-bis (4-hydroxyphenyl) -1-phenylethane and 1, 1-bis (4-hydroxyphenyl) -3, 3, 5-trimethylcyclohexane. These compounds may be used alone, or 2 or more kinds may be mixed and used.

More specifically, the polyarylate preferably comprises a structural unit represented by the following formula (B-1) and/or a structural unit represented by the following formula (B-2). Wherein represents a binding site.

Formula (B-1)

In the formula (B-1), X⁸The following structure is shown.

R⁵And R⁶Is an alkyl group or a hydrogen atom, at least one of which is preferably a methyl group, and both of which are more preferably methyl groups.

The structural unit represented by the formula (B-1) is formed, for example, from at least 1 of bisphenol A and derivatives thereof and at least 1 of terephthalic acid and isophthalic acid and derivatives thereof. The molar ratio of terephthalic acid to isophthalic acid is preferably 40 to 60: 60 to 40.

Formula (B-2)

In the formula (B-2), R⁸Each independently represents a hydrogen atom, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, an alkyl group having 1 to 9 (preferably 1 to 3) carbon atoms, an aryl group having 6 to 12 (preferably 6 to 10) carbon atoms, an alkoxy group having 1 to 5 (preferably 1 to 3) carbon atoms, an alkenyl group having 2 to 5 (preferably 2 or 3) carbon atoms, or an aralkyl group having 7 to 17 (preferably 7 to 11) carbon atoms. q represents an integer of 1 to 5.

R⁸Independently of each other, a hydrogen atom or an alkyl group having 1 to 9 (preferably 1 to 3) carbon atoms is preferable, and a hydrogen atom or a methyl group is more preferable.

The structural unit represented by the formula (B-2) is preferably a structural unit represented by the formula (B-3).

Formula (B-3)

In the formula (B-3), R⁸With R in the formula (B-2)⁸Similarly, the preferred ranges are also the same.

The structural unit represented by the formula (B-3) is formed, for example, from at least 1 of bisphenol TMC and derivatives thereof and at least 1 of terephthalic acid and isophthalic acid and derivatives thereof. The molar ratio of terephthalic acid to isophthalic acid is preferably 40 to 60: 60 to 40.

The first embodiment of the polyarylate used in the present invention is an embodiment comprising 90 mol% or more of the structural units represented by the formula (B-1) of all the structural units other than the both terminals.

The second embodiment of the polyarylate used in the present invention preferably contains the structural unit represented by the formula (B-1) and the structural unit represented by the formula (B-2) at a molar ratio of 90 to 40: 10 to 60, more preferably 90 to 51: 10 to 49, and still more preferably 85 to 55: 15 to 45. The structural unit represented by the formula (B-1) and the structural unit represented by the formula (B-2) may be contained in the same polyarylate, or may be a blend of a polyarylate containing the structural unit represented by the formula (B-1) and a polyarylate containing the structural unit represented by the formula (B-2). In the second embodiment, the polyarylate used in the present invention more preferably contains the structural unit represented by the formula (B-1) and the structural unit represented by the formula (B-2) in a total amount of 90 mol% or more of all the structural units except for both terminals.

The weight average molecular weight of the polyarylate is preferably 25,000 or more, more preferably 30,000 or more, still more preferably 35,000 or more, further preferably 37,000 or more, and may be 40,000 or more. The upper limit of the weight average molecular weight of the polyarylate is preferably 80,000 or less, more preferably 60,000 or less, and still more preferably 50,000 or less.

The measurement of the weight average molecular weight of polyarylate was performed by gel permeation chromatography as follows.

The gel permeation chromatography apparatus used was an LC-20 AD system (manufactured by Shimadzu corporation) and used as a column connecting LF-804 (manufactured by Shodex corporation). The column temperature was set to 40 ℃. The detector used was an RI detector of RID-10A (manufactured by Shimadzu corporation). Chloroform was used as an eluent, and a calibration curve was prepared using standard polystyrene manufactured by Tosoh corporation.

When the gel permeation chromatography apparatus, column and detector are difficult to obtain, the measurement is performed using another apparatus or the like having equivalent performance.

The glass transition temperature of the polyarylate as measured by a differential scanning calorimeter is preferably more than 160 ℃, more preferably 170 ℃ or more, still more preferably 180 ℃ or more, and further preferably 190 ℃ or more. The upper limit of the glass transition temperature is preferably 250 ℃ or lower, and may be 240 ℃ or lower, 230 ℃ or lower, 220 ℃ or lower, or 200 ℃ or lower. When the lower limit value is not less than the above-mentioned lower limit value, the heat resistance of the obtained base material can be further improved, and when the upper limit value is not more than the above-mentioned upper limit value, the melt viscosity can be brought to a more appropriate range.

The base material may contain additives in addition to the above resin components. Examples of the additive include at least 1 selected from the group consisting of a heat stabilizer, an antioxidant, a flame retardant aid, an ultraviolet absorber, a mold release agent, and a colorant. Further, an antistatic agent, a near infrared ray shielding agent, a light diffusing agent, a fluorescent whitening agent, an antifogging agent, a flowability improver, a plasticizer, a dispersant, an antibacterial agent, and the like may be added to the base material.

Examples of the antioxidant include a phenol-based antioxidant, an amine-based antioxidant, a phosphorus-based antioxidant, and a thioether-based antioxidant. Among these, in the present invention, a phosphorus antioxidant and a phenol antioxidant (more preferably, a hindered phenol antioxidant) are preferable. The phosphorus-based antioxidant is particularly preferable because the base material has an excellent hue. The phosphorus-based antioxidant is described in paragraphs 0098 to 0106 of Japanese patent application laid-open No. 2018 and 178075, the contents of which are incorporated herein by reference.

The total amount of the additives in the base material is preferably 0 to 10% by mass, and more preferably 0 to 5% by mass.

Next, the layer structure of the base material will be explained.

The substrate may be a single layer or a plurality of layers. In the case of a multilayer, for example, a substrate obtained by laminating an acrylic resin layer such as a poly (meth) acrylic acid methyl resin (PMMA: polymethyl acrylate and/or polymethyl methacrylate) on a layer of Polycarbonate (PC), a substrate obtained by laminating a layer of Polycarbonate (PC) on a layer of Polycarbonate (PC), and the like can be cited. The substrate used in the present invention is preferably a single layer.

< adhesive layer >

The sheet of the present invention includes the adhesive layer provided on the substrate as described above.

The kind of the adhesive layer is not particularly limited, and preferably includes at least 1 of an acrylic adhesive, a silicone adhesive, and a polyurethane adhesive. By using these adhesives, higher adhesiveness and appropriate adhesion to, for example, an undercoat layer can be achieved.

The adhesive layer may have removability, and the adhesive layer having removability can be bonded again even if it is once peeled from the patch.

The acrylic adhesive is an adhesive containing an acrylic polymer, and specific examples thereof include FINETAC (CT-3088, CT-3850, CT-6030, CT-5020, CT-5030) manufactured by DIC, Quick Master (SPS-900-IV, Quick Master SPS-1040 NT-25) manufactured by Toyo-chem, and adhesive ORIBAIN manufactured by Toyo-chem.

The silicone adhesive is an adhesive containing a silicone polymer, and specific examples thereof include polymers produced by KR-3704 (base compound) and CAT-PL-50T (platinum catalyst) manufactured by shin-Etsu chemical Co., Ltd.

The polyurethane adhesive is an adhesive containing a polyurethane polymer, and specific examples thereof include an adhesive ORIBAIN manufactured by Toyo-chem corporation.

In the present specification, the polymer means a compound having a number average molecular weight of 1000 or more, preferably 2000 or more.

In addition to the above, the adhesive layer described in paragraphs 0026 to 00053 of jp 2017-200975 a, the adhesive layer described in paragraphs 0056 to 0060 of jp 2013-020130 a, the adhesive sheet described in international publication No. 2016/158827, the adhesive layer described in paragraphs 0031 to 0032 of jp 2016-182791 a, and the rubber-based adhesive layer described in paragraphs 0057 to 0084 of jp 2015-147837 a may be used as the adhesive layer without departing from the scope of the present invention, and these contents are incorporated into the present specification.

The thickness of the adhesive layer is not particularly limited, but is preferably 10 μm or more, more preferably 25 μm or more, still more preferably 35 μm or more, and may be 40 μm or more. The thickness of the adhesive layer is preferably 70 μm or less, more preferably 60 μm or less. By setting the range as described above, more suitable adhesion properties and adhesion strength can be achieved.

Next, the peeling force of the adhesive layer will be described.

In the present invention, an adhesive sheet for bonding comprising a substrate containing a polycarbonate and an adhesive layer provided on the substrate, the adhesive sheet for bonding having a glass transition temperature of the substrate of 160 ℃ or higher as measured by differential scanning calorimetry is laminated on a polycarbonate mirror surface film having a thickness of 0.1(mm) on the adhesive layer side, and preferably exhibits a peel force of 0.001 to 4.5N/25mm in a peel test of peeling under the condition of 152 mm/min in a direction of 180 ° in accordance with JIS Z0237. When the lower limit value is not less than the above-described lower limit value, the adhesive strength tends to be further improved. The peeling force is more preferably 0.005N/25mm or more, and still more preferably 0.01N/25mm or more. The peeling force is more preferably 3N/25mm or less, still more preferably 1N/25mm or less, still more preferably 0.8N/25mm or less, still more preferably 0.7N/25mm or less, still more preferably 0.5N/25mm or less, and may be 0.2N/25mm or less. An adhesive sheet having excellent removability can be obtained by setting the peel force to 3N/25mm or less, and further 1N/25mm or less.

The peel force was measured by the method described in the examples described later.

The peel force can be controlled by the composition of the adhesive layer. For example, in the case of a silicone adhesive layer, the peeling force can be adjusted by the main chain structure, terminal structure, branched structure, molecular weight, and the like of the polyorganosiloxane constituting the layer. In the case of a polyurethane adhesive layer, the peeling force can be adjusted by the main chain structure or molecular weight of the polyol and polyisocyanate constituting the adhesive layer, the ratio of these, and the like. In the case of the acrylic adhesive layer, the peeling force can be adjusted by the monomer structure or molecular weight of the acrylic resin, the copolymerization ratio, the main chain structure or molecular weight of the polyisocyanate, the ratio of the acrylic resin to the polyisocyanate, and the like.

Further, an adhesive layer having an arbitrary peeling force may be formed by combining adhesives having different adhesive forces.

< undercoat layer >

The adhesive sheet of the present invention may have a primer layer as described above. The primer layer is provided between the base material layer and the adhesive layer, and has an effect of improving the bondability between the adhesive layer and the base material layer. In addition, chemical cracking and the like of the substrate due to the solvent used in forming the adhesive layer can be suppressed.

The primer layer preferably comprises a urethane (meth) acrylate resin. By using the urethane (meth) acrylate resin, an adhesive sheet having more excellent heat resistance can be obtained.

Polyurethane (meth) acrylate resin

(urethane (meth) acrylate resin having a molecular structure containing a cyclic skeleton)

The urethane (meth) acrylate resin is preferably a urethane (meth) acrylate resin having a molecular structure containing a cyclic skeleton. More specifically, a preferable specific example of the urethane (meth) acrylate is a polymer of an isocyanate compound having a cyclic skeleton and an acrylate compound. The urethane (meth) acrylate resin which may have a molecular structure of a cyclic skeleton is preferably an ultraviolet-curable type.

The isocyanate compound may be, for example, an aromatic isocyanate which may have an alkyl substituent such as a methyl group, preferably an aromatic isocyanate having 6 to 16 carbon atoms in total, more preferably an aromatic isocyanate having 7 to 14 carbon atoms, and particularly preferably an aromatic isocyanate having 8 to 12 carbon atoms.

As the isocyanate, aromatic isocyanates are preferable, but aliphatic isocyanates, alicyclic isocyanates, and the like can be used.

Examples of the (meth) acrylate compound include pentaerythritol triacrylate (PETA), dipentaerythritol pentaacrylate (DPPA), and hydroxypropyl (meth) acrylate (hydroxypropyl acrylate: HPA).

Further, as the (meth) acrylate compound, a compound having a (meth) acryloyloxy group and a hydroxyl group, for example, a monofunctional (meth) acrylic compound having a hydroxyl group, may also be used.

Preferable specific examples of the urethane (meth) acrylate resin, which is a polymer of the isocyanate compound and the (meth) acrylate compound, include a polymer of Xylylene Diisocyanate (XDI) and pentaerythritol triacrylate (PETA), a polymer of XDI and dipentaerythritol pentaacrylate (DPPA), a polymer of dicyclohexylmethane diisocyanate (H12MDI) and PETA, a polymer of isophorone diisocyanate (IPDI) and PETA, and a polymer of XDI and hydroxypropyl (meth) acrylate (HPA).

The urethane (meth) acrylate having a cyclic skeleton includes a polymer containing a polyol compound as a constituent unit in addition to the isocyanate compound and the (meth) acrylate compound. Examples of the polyol compound (polyhydric alcohol) include compounds having 2 or more hydroxyl groups in 1 molecule.

Preferred specific examples of the urethane (meth) acrylate resin include polymers of Tricyclodidecyldimethanol (TCDDM), IPDI and PETA, polymers of TCDDM, H12MDI and PETA, polymers containing DPPA as a structural unit together with PETA instead of PETA, and polymers containing Xylylene Diisocyanate (XDI) and hydroxypropyl (meth) acrylate (HPA).

The urethane (meth) acrylate containing a polyol compound as a structural unit in addition to the isocyanate compound and the compound having a (meth) acryloyloxy group preferably contains at least a component represented by the following formula (I).

(A³)－O(O＝)CHN－A²－HNC(＝O)O－A¹－O(O＝)CNH－A²－NH－(＝O)O－(A³)···(I)

In the formula (I), the compound represented by the formula (I),

A¹is an alkylene group derived from the above-mentioned polyol compound,

A²independently of one another, are alkylene groups derived from the isocyanate compounds mentioned above,

A³each independently represents an alkyl group derived from the above-mentioned compound having a (meth) acryloyloxy group and a hydroxyl group.

Preferred specific examples of the urethane (meth) acrylate contained in the resin component include the following compounds containing structural units derived from ethylene glycol, pentaerythritol triacrylate and isophorone diisocyanate. In the formula, n is 0 to 10, preferably 1 to 5, and more preferably 1 to 3.

In the urethane (meth) acrylate resin, the ratio of the structural unit derived from the compound having a (meth) acryloyloxy group and a hydroxyl group to the structural unit derived from isocyanate is preferably 99: 1 to 30: 70 (mass ratio), more preferably 97: 3 to 60: 40, and still more preferably 95: 5 to 80: 20.

(urethane (meth) acrylate containing (meth) acrylate)

As a preferable specific example of the urethane (meth) acrylate resin, a resin containing urethane (meth) acrylate and (meth) acrylate (meaning (meth) acrylate other than urethane (meth) acrylate, preferably (meth) acrylate having a molecular weight of 1000 or less, the same applies hereinafter) can be cited. As a more preferable specific example of such a urethane (meth) acrylate resin, a resin containing a mixture of 6-functional urethane (meth) acrylate and 2-functional (meth) acrylate is exemplified.

The ratio of urethane (meth) acrylate to (meth) acrylate in the urethane (meth) acrylate resin is preferably 99: 1 to 30: 70 (mass ratio), more preferably 97: 3 to 60: 40, and still more preferably 95: 5 to 80: 20.

As described above, when the undercoat layer is formed from a mixture of urethane (meth) acrylate and (meth) acrylate, adhesion to the substrate and bendability of the undercoat layer can be improved.

In the present invention, the urethane (meth) acrylate is preferably a urethane acrylate.

In the primer coating material which is a material for forming the primer layer, as resin components other than urethane (meth) acrylate and (meth) acrylate, for example, epoxy (meth) acrylate, acrylic (meth) acrylate, and resin components, an antistatic agent, an ultraviolet absorber (ultraviolet screening agent), a near-infrared screening agent, a light diffusing agent typified by silica, metal particles, or the like may be added. The total amount of these components is preferably 5 mass% or less of the solid content (component to become the undercoat layer) of the undercoat coating material.

The undercoat paint may further contain any of a leveling agent and a photopolymerization initiator. The undercoat paint may contain a solvent. The solvent of the undercoat paint is preferably a solvent that does not affect the resin component of the substrate, and propylene glycol monomethyl ether and the like are particularly preferred.

By adding a leveling agent to the undercoat paint, the surface of the coating film in the drying process is made to have orientation, the surface tension of the coating film is made uniform and reduced, and floating or wrinkling is prevented, enabling the wettability to the substrate to be improved. As the leveling agent, for example, a silicone surfactant, an acrylic surfactant, a fluorine surfactant, or the like can be suitably used.

In the undercoat paint, the resin component is contained preferably at least 80 mass%, more preferably at least 90 mass%, and still more preferably at least 95 mass%, based on the mass of the solid component (component to become the undercoat layer) as the undercoat paint. The resin component preferably contains 80 mass% or more of urethane (meth) acrylate.

In addition to the above, reference can be made to paragraphs 0012 to 0019 and paragraphs 0029 to 0030 of Japanese patent application laid-open No. 2016 and 182791 and paragraphs 0051 to 0056 of Japanese patent application laid-open No. 2015 and 147837, and these contents are incorporated into the present specification.

The thickness of the undercoat layer is not particularly limited, but is preferably 2 μm or more, and more preferably 2.5 μm or more. When the lower limit value is not less than the above-described lower limit value, the whitening phenomenon of the base material due to the solvent can be more effectively suppressed when the adhesive layer is applied. The thickness of the undercoat layer is preferably 10 μm or less, more preferably 7 μm or less, and still more preferably 5 μm or less. By setting the upper limit value or less, cracks can be made less likely to occur at the time of bending or the like.

< hard coating >

The adhesive sheet of the present invention may have a hard coat layer as described above. By providing the hard coat layer, the surface hardness of the adhesive sheet tends to be increased. The thickness of the hard coat layer is not particularly limited, but is preferably 1 to 10 μm, more preferably 2 to 8 μm, and still more preferably 3 to 7 μm.

The hard coat layer is preferably formed on a surface of the substrate without laminating the primer layer.

The hard coat layer is preferably formed by subjecting the surface of a substrate or the like to a hard coat treatment. That is, it is preferable to laminate a hard coat layer by applying a hard coat material curable by heat curing or active energy ray and then curing the material.

Examples of the active energy ray-curable coating material include a resin composition composed of a single or plural kinds of 1-functional or polyfunctional (meth) acrylate monomers or oligomers, and more preferably a resin composition containing a urethane (meth) acrylate oligomer. These resin compositions are preferably added with a photopolymerization initiator as a curing catalyst.

Examples of the thermosetting resin coating material include polyorganosiloxane-based resin coating materials and crosslinking acrylic resin coating materials. Such a resin composition is also commercially available as a hard coating agent for acrylic resin or polycarbonate, and may be appropriately selected in consideration of compatibility with a coating line.

As the hard coat layer, reference may be made to the descriptions in paragraphs 0045 to 0055 of japanese patent application laid-open No. 2013-020130, paragraphs 0073 to 0076 of japanese patent application laid-open No. 2018-103518, and paragraphs 0062 to 0082 of japanese patent application laid-open No. 2017-213771, and these contents are incorporated in the present specification.

[ method for producing adhesive sheet ]

In the production of the adhesive sheet, the base material is preferably formed first. In the production of the substrate, the resin composition for molding a substrate containing polycarbonate is processed into a sheet (film) shape by a known method. Specifically, the molding can be performed by extrusion molding or cast molding. In the present invention, it is particularly preferable that the resin composition for molding a substrate containing polycarbonate and no solvent is melted and extrusion-molded to prepare a substrate. Examples of extrusion molding include a method in which pellets, flakes, or powder of the resin composition is melted and kneaded by an extruder, extruded from a T die or the like, and the resulting semi-molten sheet is cooled and solidified while being nipped by a roll to form a sheet. In addition, a commercially available polycarbonate film may be used.

The adhesive sheet can be produced by a production method including an undercoat layer formation step and an adhesive layer formation step, for example, as described below, using the substrate containing polycarbonate.

In the undercoat layer forming step, an undercoat coating material (undercoat liquid) is applied to the surface of the substrate and cured to form an undercoat layer.

In the adhesive layer forming step, an adhesive is applied to the opposite surface of the formed primer layer to the surface in contact with the substrate and cured to form an adhesive layer.

As a method for curing the undercoat paint or the adhesive, a method such as photo-curing or thermal curing can be used.

[ multilayer body ]

The multilayer body of the present invention is characterized in that the adhesive sheet of the present invention is adhered to at least a part of the surface of the resin molded body on the adhesive layer side. The resin molded article is a resin molded article, and means an adherend to which the adhesive sheet of the present invention is bonded. The shape of the resin molded article is not particularly limited, and may be a part or a finished product, and the surface may be smooth, may have irregularities, or may have a complicated shape. In the present invention, an embodiment in which the resin molded article is a resin sheet can be exemplified.

The resin molded body is preferably a material having excellent heat resistance and transparency. The resin molded body is preferably an amorphous resin having a Tg of 160 ℃ or higher, preferably contains polycarbonate, polyarylate, cycloolefin, or polyimide, and more preferably contains polycarbonate or polyimide.

The method for producing a multilayer body of the present invention includes a step of attaching the adhesive sheet for bonding of the present invention to a resin molded body.

As a method for bonding the resin molded article and the adhesive sheet, a known method can be used. Examples thereof include direct manual application, roll lamination, and water application.

< use >)

The adhesive sheet and multilayer body of the present invention can be used as a material for constituting various elements of image display devices such as mobile phone terminals, smart phones, portable electronic game machines, mobile information terminals, tablet personal computer devices, mobile computers, wearable terminals, and the like, and display devices such as liquid crystal televisions, liquid crystal monitors, desktop computers, car navigation devices, automobile instruments, and the like.

The transparent conductive film can be suitably used as a substrate material or a protective material for the transparent conductive film or various elements of the liquid crystal member.

The adhesive sheet and the multilayer body of the present invention can be processed by various processing methods. For example, a method using heating and pressing with a mold, and a pressure air molding method, a vacuum molding method, a roll molding method, and the like can be exemplified as the molding method. The adhesive sheet or multilayer body of the present invention can be used for an element having a curved surface by processing.

In addition to the above, the present invention can refer to the descriptions of international publication No. 2016/158827, japanese patent application laid-open nos. 2017-200975 and 2015-147837, and these contents are incorporated into the present specification, without departing from the gist of the present invention.

Examples

The present invention will be described in more detail with reference to examples. The materials, the amounts used, the ratios, the contents of the processes, the processing steps, and the like shown in the following examples can be appropriately modified without departing from the spirit of the present invention. Therefore, the scope of the present invention is not limited to the specific examples shown below.

[ base Material ]

< raw materials >

An aromatic polycarbonate resin obtained by an interfacial polymerization method using bisphenol AP as a starting material (FPC-0220, Mitsubishi gas chemical, viscosity average molecular weight 20,200)

An aromatic polycarbonate resin obtained by an interfacial polymerization method using bisphenol A as a starting material (H-4000F, manufactured by Mitsubishi engineering plastics Co., Ltd., viscosity average molecular weight 16,000)

An aromatic polycarbonate resin obtained by an interfacial polymerization method using bisphenol A as a starting material (H-7000F, manufactured by Mitsubishi engineering plastics corporation, viscosity average molecular weight 14,000)

An aromatic polycarbonate resin obtained by an interfacial polymerization method using bisphenol A as a starting material (S-3000F, Mitsubishi engineering plastics, viscosity average molecular weight 21,000)

Aromatic polyarylate starting from bisphenol A (U-powder type L, manufactured by Uygur autonomous corporation, dicarboxylic acid component: terephthalic acid/isophthalic acid: 50/50 mol%, bisphenol component: bisphenol A: 100 mol%, weight average molecular weight: 40,800)

Bis (2, 6-di-tert-butyl-4-methylphenyl) pentaerythritol diphosphite, phosphorus antioxidant, manufactured by ADEKA K.K., ADK STAB PEP-36

3, 9-bis [ 2- { 3- (3-tert-butyl-4-hydroxy-5-methylphenyl) propionyloxy }1, 1-dimethylethyl ] -2, 4,8, 10-tetraoxaspiro [5,5] undecane, phosphorus antioxidant, manufactured by ADEKA, ADK STAB AO-80

< production of base sheet 1,2 >

PEP-36 (0.005 part by mass) and AO-80 (0.03 part by mass) were added in amounts to FPC-0220 (45 parts by mass) and H-4000F (55 parts by mass), and after mixing for 15 minutes with a tumbler, they were melt-kneaded at a cylinder temperature of 320 ℃ by a twin-screw extruder (TEX 30. alpha. manufactured by Nippon Steel works) with a vent, and pellets were obtained by strand cutting.

The pellets thus obtained were extruded in a molten state at a discharge rate of 10kg/h and a screw rotation speed of 63rpm using a T die melt extruder constituted by a double screw extruder with an opening having a cylinder diameter of 32mm and a screw L/D of 31.5 (TEX 30. alpha. manufactured by Nippon Steel works Co., Ltd.), pressed between a first roll (mirror surface rubber roll, temperature 50 ℃ C.) and a second roll (rigid mirror surface roll, temperature 130 ℃ C.), cooled and solidified to prepare sheets. At a cylinder/die temperature of 300 ℃. At this time, by adjusting the discharge amount and the roll pulling speed, a sheet (base sheet 1) having a thickness of 50 μm and a sheet (base sheet 2) having a thickness of 100 μm were obtained, respectively.

< production of base sheet 3 >

In the production of the base sheet 1, a sheet (base sheet 3) having a thickness of 50 μm was produced in the same manner as in the production of the base sheet 1 except that the FPC-0220 (45 parts by mass) and the H-4000F (55 parts by mass) were changed to the U-powder L type (50 parts by mass) and the H-7000F (50 parts by mass).

< production of base sheet 4 >

In the production of the base sheet 1, a sheet (base sheet 4) having a thickness of 50 μm was produced in the same manner as in the production of the base sheet 1 except that the FPC-0220 (45 parts by mass) and the H-4000F (55 parts by mass) were changed to S-3000F (100 parts by mass). < determination of glass transition temperature (Tg) of substrate >

The glass transition temperature (Tg) of the substrate was measured by performing two cycles of temperature increase and temperature decrease under the following measurement conditions of DSC, and measuring the glass transition temperature at the time of temperature increase in the second cycle.

The intersection of a straight line extending from the base line on the low temperature side to the high temperature side and a tangent to the inflection point is defined as a glass transition start temperature, the intersection of a straight line extending from the base line on the high temperature side to the low temperature side and a tangent to the inflection point is defined as a glass transition end temperature, and the midpoint between the glass transition start temperature and the glass transition end temperature is defined as a glass transition temperature (Tg). Conditions were measurement start temperature: 30 ℃ and temperature rise rate: 10 ℃/min, reach temperature: 250 ℃ and cooling rate: 20 deg.C/min.

A differential scanning calorimeter (DSC, manufactured by Hitachi Kagaku K.K., "DSC 7020") was used as a measuring apparatus.

< determination of retardation (Re) of substrate >

The refractive index n in the direction in which the maximum refractive index was obtained in the in-plane direction of the base sheet was measured using an ellipsometer_xAnd the in-plane direction n_xIs in a direction perpendicular to the direction of the refractive index n_y. From these n_x、n_yThe retardation (Re) (cell: nm) was calculated. 5 base material sheets of 50X 50mm size were cut out, and the respective Re's were measured. The average value of the obtained Re was used as the retardation (Re) of the substrate.

Conditions for measurement

A light splitting mode: double single color mode

Measuring wavelength: 550nm

Incident angle: 90 degree

Bandwidth: 0.5mm

Responding: 2sec

Start and end elevation angles of the anisotropic resolution stage: -50 °,50 °

Measurement interval: 5 degree

The ellipsometer used was M-220 manufactured by Nippon spectral Co.

< determination of haze >

The haze (%) of the substrate was measured using a haze meter according to JIS-K-7361 and JIS-K-7136 under the condition of a D65 light source with a field of view of 10 °.

As the haze meter, "HM-150" (trade name) manufactured by color technology research institute on village was used.

[ preparation of undercoat paint ]

A6-functional urethane acrylate (trade name UN-3320 HC, manufactured by Kokusho industries, Ltd.), 90 parts by mass of a 2-functional urethane acrylate (trade name VEEA, manufactured by Japan catalyst Co., Ltd.), and 5 parts by mass of a photopolymerization initiator Irgacure-184 (Omnirad 184, manufactured by BASF, sold by IGM Resins B.V. Co., Ltd., at present as a substitute) were mixed together, and the mixture was prepared so that the solid content thereof became 30% by mass using propylene glycol monomethyl ether as a solvent, to obtain an undercoat paint.

[ preparation of Silicone adhesive coating 1 (Silicone 1) ]

To 100 parts by mass of an organosilicon compound (trade name KR-3704, manufactured by shin-Etsu chemical Co., Ltd.) was added 0.5 part by mass of a platinum catalyst (trade name CAT-PL-50T, manufactured by shin-Etsu chemical Co., Ltd.) for curing, and the mixture was thoroughly mixed and diluted with toluene as a solvent to obtain a solid content of 40% by mass, thereby obtaining an organosilicon adhesive coating material 1.

[ preparation of polyurethane adhesive coating 1 (polyurethane 1) ]

To 100 parts by mass of a base (product name CYABINE SH-101, manufactured by Toyo-chem Co., Ltd.) was added 4 parts by mass of a curing agent (product name T-501B, manufactured by Toyo-chem Co., Ltd.), and the mixture was thoroughly mixed to obtain a polyurethane adhesive solution coating 1.

[ preparation of polyurethane adhesive coating 2 (polyurethane 2) ]

To 100 parts by mass of a base (product name CYABINE SH-205, manufactured by Toyo-chem Co., Ltd.) was added 3 parts by mass of a curing agent (product name T-501B, manufactured by Toyo-chem Co., Ltd.), and the mixture was thoroughly mixed to obtain a polyurethane adhesive solution coating 2.

[ preparation of acrylic adhesive coating 1 (acrylic acid 1) ]

1.5 parts by mass of a curing agent (trade name D-100K, manufactured by DIC) was added to 100 parts by mass of a base (trade name FINETAC CT-3088, manufactured by DIC) and mixed thoroughly to obtain an acrylic adhesive coating 1.

[ film to be adhered ]

Films of Polycarbonate (PC)

A100 μm mirror film (FS-2000, manufactured by MGC Flex Tekken Co., Ltd.) made of bisphenol A polycarbonate was used.

Polyimide (PI) film

A film produced by the following production example.

< production of PI film >

In a 5-neck glass round-bottomed flask having a stainless steel half-moon-shaped stirring paddle, a nitrogen introduction tube, a dean-Stark apparatus equipped with a cooling tube, a thermometer, and a glass end cap, 29.034g (0.056 mol) of 2, 2-bis [ 4- (4-aminophenoxy) phenyl ] Hexafluoropropane (HFBAPP), 18.76g (0.014 mol) of X-22-9409, 50g of gamma-butyrolactone (manufactured by Mitsubishi chemical Co., Ltd.), 0.039g of triethylenediamine (manufactured by Tokyo chemical Co., Ltd.) as a catalyst, and 3.54g of triethylamine (manufactured by Kanto chemical Co., Ltd.) were stirred at 200rpm under a nitrogen atmosphere to obtain a solution. To this solution, 15.692g (0.070 mol) of 1,2,4, 5-cyclohexanetetracarboxylic dianhydride (HPMDA) and 13.5g of γ -butyrolactone (Mitsubishi chemical corporation) were added in one portion, and then the mixture was heated by a mantle heater for about 20 minutes to raise the temperature in the reaction system to 200 ℃. The distilled components were collected, and the temperature in the reaction system was maintained at 200 ℃ for 3 hours. 78.76g of N, N-dimethylacetamide (manufactured by Mitsubishi gas chemical corporation) was added thereto, and the mixture was stirred at about 100 ℃ for about 1 hour to obtain a uniform polyimide varnish having a solid content of 30 mass%.

Next, the obtained polyimide varnish was coated on a PET substrate, and held at 100 ℃ for 30 minutes, and the solvent was evaporated to obtain a colorless transparent primary dried film having self-supporting properties. The film was fixed on a stainless steel frame and dried at 230 ℃ under nitrogen atmosphere for 2 hours, whereby the solvent was removed to obtain a PI film having a thickness of 40 μm.

[ example 1]

The base sheet 1 obtained by the above method was coated with the undercoat paint 1 so that the dried coating film became 3 μm, and dried at 100 ℃ for 2 minutes by a hot air circulation dryer. Further, the cumulative light amount was 200mJ/cm by using an ultraviolet curing device²The method (3) is to irradiate ultraviolet rays to obtain a primer-treated sheet having a primer layer formed on the surface of a substrate.

Next, the silicone adhesive coating 1 was applied to the surface of the undercoat-layer side of the undercoat-treated sheet by a bar coater so that the thickness of the dried coating film became 40 μm, and dried at 120 ℃ for 1 minute by a hot air circulation dryer to form an adhesive layer.

Thus, an adhesive sheet of example 1 was obtained.

< peeling force >

The adhesive sheet obtained above was laminated on a PC film to be bonded on the adhesive layer side by means of a laminator (MP-630, manufactured by MCK Co., Ltd.), and a peel test (tensile test) was carried out according to JIS Z0237 by a tensile tester (auto graph AGS-X, manufactured by Shimadzu corporation) in a 180 ℃ direction under a condition of 152 mm/min to measure the peel force (cell: N/25 mm).

Test method the peel strength of the adhesive layer to a Polycarbonate (PC) film was evaluated by a 180 ° peel test with reference to "adhesive tape/adhesive sheet test method" specified in JIS Z0237. That is, the peel force of the adhesive tape to a predetermined test plate was measured in JIS Z0237, but in example 1 and the like, the peel force was measured by bonding to a substrate. Thus, the peel force was evaluated by a method in which only the kind of the test plate was different from JIS Z023.

< sticking test >

The adhesive sheet cut to a4 size was laminated on each of the films to be adhered by a film laminator (MP-630 manufactured by MCK) to confirm the appearance of the laminated multilayer body. The evaluation was performed by 10 persons, using the evaluation results selected by the most persons.

Lamination conditions

Lamination speed: 1.8 m/min

Left and right nip: 0.3MPa

A: can be laminated without affecting the appearance.

B: in the case other than the above-mentioned a, for example, poor appearance occurs in lamination.

< Repeatability >

The adhesive sheet obtained above was laminated on each film to be attached by a film laminator (MP-630, manufactured by MCK), cut to a size of 150mm × 150mm, and left to stand at 23 ℃ under a Relative Humidity (RH) of 50% for 24 hours, and then the appearance of the film to be attached was confirmed when the adhesive sheet was peeled off. The evaluation was performed by 10 persons, using the evaluation results selected by the most persons.

A: can be peeled off without affecting the appearance.

B: the appearance was slightly affected, but could be peeled off.

C: other than A, B, the base material may be deformed during peeling to prevent further peeling.

< Heat resistance test >

The adhesive sheets of the A4-sized examples and comparative examples were laminated on a PI film to be adhered by a film laminating machine (MP-630, manufactured by MCK Co., Ltd.), cut to a size of 150mm X150 mm, placed in an oven (DKN 402, manufactured by YAMATO scientific Co., Ltd.) and allowed to stand at 140 ℃ for 3 hours, and after taking out, the warpage was observed when the sheets were allowed to stand in a room at 23 ℃ for 30 minutes. In the determination of the warpage amount evaluation, the sticking object film in which warpage has occurred was left on a horizontal table so as to protrude downward, warpage amounts from the horizontal surface of the table on which the sticking object film was placed to 4 corners of the film were measured with a ruler, and an average value of the warpage amounts at 4 corners was calculated. The measurement was performed 5 times, and the average value was calculated for 5 times.

A: the average value of the warping amount is less than 1 mm.

B: the average value of the warpage amount is 1mm or more.

[ example 2]

A bonded sheet of example 2 was obtained in the same manner as in example 1, except that the base sheet 1 was changed to the base sheet 2 in example 1.

[ example 3]

An adhesive sheet of example 3 was obtained in the same manner as in example 1, except that the silicone adhesive coating 1 was changed to the urethane adhesive coating 1 in example 1.

[ example 4]

An adhesive sheet of example 4 was obtained in the same manner as in example 1, except that the silicone adhesive coating 1 was changed to the acrylic adhesive coating 1 in example 1.

[ example 5]

The same procedure as in example 1 was repeated except that the base sheet 1 was changed to the base sheet 3 in example 1 to obtain an adhesive sheet of example 5.

[ example 6]

An adhesive sheet of example 6 was obtained in the same manner as in example 1, except that the silicone adhesive coating material 1 was changed to the urethane adhesive 2 in example 1.

Comparative example 1

An adhesive sheet of comparative example 1 was obtained in the same manner as in example 1, except that the substrate 1 was changed to the substrate 4 in example 1.

[ Table 1]

Description of the symbols

10: bonding the sheet material; 12: an adhesive layer; 16: a primer layer; 20: a substrate.

Claims

1. An adhesive sheet for bonding, characterized by comprising:

a substrate comprising polycarbonate; and

an adhesive layer disposed on the base material,

2. The adhesive sheet for attachment according to claim 1, wherein:

the polycarbonate contained in the base material comprises 100-10 mass% of bisphenol AP type polycarbonate and 0-90 mass% of bisphenol A type polycarbonate, wherein the total mass of the bisphenol AP type polycarbonate and the bisphenol A type polycarbonate is not more than 100 mass%.

3. The adhesive sheet for attachment according to claim 1 or 2, wherein:

the base material contains 10-90 parts by mass of polyarylate per 100 parts by mass of the resin component contained in the base material.

4. The bonding sheet for bonding according to any one of claims 1 to 3, wherein:

the substrate has a glass transition temperature of 200 ℃ or lower as measured by differential scanning calorimetry.

5. The bonding sheet for bonding according to any one of claims 1 to 4, wherein:

the adhesive layer contains an acrylic adhesive.

6. The bonding sheet for bonding according to any one of claims 1 to 5, wherein:

the adhesive layer contains a silicone adhesive.

7. The bonding sheet for bonding according to any one of claims 1 to 6, wherein:

the adhesive layer contains a polyurethane adhesive.

8. The bonding sheet for bonding according to any one of claims 1 to 7, wherein:

the in-plane retardation Re of the substrate is 100nm or less.

9. The bonding sheet for bonding according to any one of claims 1 to 8, wherein:

the haze of the base material is 0% to 1.5%.

10. The bonding sheet for bonding according to any one of claims 1 to 9, wherein:

the thickness of the base material is 30-200 [ mu ] m.

11. The bonding sheet for bonding according to any one of claims 1 to 10, wherein:

the thickness of the adhesive layer is 10 [ mu ] m to 70 [ mu ] m.

12. The bonding sheet for bonding according to any one of claims 1 to 11, wherein:

the sheet is laminated on a polycarbonate mirror surface film on the side of the adhesive layer, and a peeling force of 0.001 to 3N/25mm is shown in a peeling test according to JIS Z0237, wherein the peeling test is performed under the condition that the sheet is peeled in a 180-degree direction at 152 mm/min.

13. The bonding sheet for bonding according to any one of claims 1 to 12, wherein:

a primer layer is provided between the substrate and the adhesive layer.

14. A multilayer body characterized by:

the adhesive layer side of the adhesive sheet for bonding according to any one of claims 1 to 13 is bonded to at least a part of the surface of a resin molded body.

15. The multilayer body of claim 14, wherein:

the resin molded body is a resin sheet.

16. The multilayer body according to claim 14 or 15, wherein:

the resin molded body contains polycarbonate.

17. The multilayer body according to claim 14 or 15, wherein:

the resin molded body contains polyimide.

18. A method of manufacturing a multilayer body, characterized by comprising:

a step of attaching the adhesive sheet for bonding according to any one of claims 1 to 13 to a resin molded body.