CN110997320A - Laminate and touch panel - Google Patents
Laminate and touch panel Download PDFInfo
- Publication number
- CN110997320A CN110997320A CN201880051251.9A CN201880051251A CN110997320A CN 110997320 A CN110997320 A CN 110997320A CN 201880051251 A CN201880051251 A CN 201880051251A CN 110997320 A CN110997320 A CN 110997320A
- Authority
- CN
- China
- Prior art keywords
- meth
- adhesive layer
- acrylate
- laminate
- layer
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B27/00—Layered products comprising a layer of synthetic resin
- B32B27/36—Layered products comprising a layer of synthetic resin comprising polyesters
- B32B27/365—Layered products comprising a layer of synthetic resin comprising polyesters comprising polycarbonates
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B27/00—Layered products comprising a layer of synthetic resin
- B32B27/36—Layered products comprising a layer of synthetic resin comprising polyesters
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B7/00—Layered products characterised by the relation between layers; Layered products characterised by the relative orientation of features between layers, or by the relative values of a measurable parameter between layers, i.e. products comprising layers having different physical, chemical or physicochemical properties; Layered products characterised by the interconnection of layers
- B32B7/04—Interconnection of layers
- B32B7/12—Interconnection of layers using interposed adhesives or interposed materials with bonding properties
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
- C08K5/00—Use of organic ingredients
- C08K5/16—Nitrogen-containing compounds
- C08K5/29—Compounds containing one or more carbon-to-nitrogen double bonds
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
- C09J133/00—Adhesives based on homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by only one carboxyl radical, or of salts, anhydrides, esters, amides, imides, or nitriles thereof; Adhesives based on derivatives of such polymers
- C09J133/04—Homopolymers or copolymers of esters
- C09J133/06—Homopolymers or copolymers of esters of esters containing only carbon, hydrogen and oxygen, the oxygen atom being present only as part of the carboxyl radical
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F3/00—Input arrangements for transferring data to be processed into a form capable of being handled by the computer; Output arrangements for transferring data from processing unit to output unit, e.g. interface arrangements
- G06F3/01—Input arrangements or combined input and output arrangements for interaction between user and computer
- G06F3/03—Arrangements for converting the position or the displacement of a member into a coded form
- G06F3/041—Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means
Landscapes
- Engineering & Computer Science (AREA)
- Theoretical Computer Science (AREA)
- General Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Human Computer Interaction (AREA)
- General Physics & Mathematics (AREA)
- Physics & Mathematics (AREA)
- Medicinal Chemistry (AREA)
- Polymers & Plastics (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Health & Medical Sciences (AREA)
- Laminated Bodies (AREA)
- Adhesives Or Adhesive Processes (AREA)
- Adhesive Tapes (AREA)
- Push-Button Switches (AREA)
Abstract
The invention provides a laminate of a polycarbonate sheet and other layers having high water absorption capacity via an adhesive layer, which is excellent in blister resistance and whitening resistance under high-durability conditions. The laminate is characterized in that the second layer is a polycarbonate sheet having a weight ratio (weight after standing/weight before standing) of 1.0010 to 1.0050 before and after standing for 72 hours in an environment of 85 ℃/85% RH (weight after standing/weight before standing), the adhesive layer is formed from an adhesive composition containing a (meth) acrylic copolymer (A) and an isocyanate-based crosslinking agent (B), the (meth) acrylic copolymer (A) is a copolymer of monomer components including a polymerizable macromonomer and a crosslinkable functional group-containing monomer, and the isocyanate-based crosslinking agent (B) has an alkyleneoxy group having 2 or more carbon atoms.
Description
Technical Field
The present invention relates to a laminate and a touch panel.
Background
In recent years, the market for smart phones and tablet computers has been expanding, and these devices are generally mounted with touch panels. Touch panels are laminates of various materials, and adhesives are used for laminating the various materials (see patent documents 1 and 2).
Polycarbonate is often used as a material for the support and the cover member (surface support) of the touch panel. The polycarbonate contains moisture due to the production process thereof, and when the adhesive sheet is stuck to a polycarbonate plate and subjected to a durability test (for example, an evaluation test of blister resistance and whitening resistance), foaming due to the moisture occurs.
Further, although the use of touch panels for automobiles is also expanding, durability higher than that of general use is required in automobile applications for the reason of high temperature and high humidity in summer. However, conventional adhesives cannot satisfy high durability conditions (high temperature and high humidity conditions) expected for automotive use.
Documents of the prior art
Patent document
Patent document 1: japanese patent laid-open publication No. 2013-018227
Patent document 2: international publication No. 2016/052276
Disclosure of Invention
Technical problem to be solved by the invention
According to the studies of the present inventors, it has been found that when a polycarbonate plate is used as an application target of an adhesive, the durability described above is not a problem when the water absorption capacity of the polycarbonate plate is low, but the durability described above is a serious problem when the water absorption capacity of the polycarbonate plate is high. The invention provides a laminate of a polycarbonate plate and other layers having high water absorption capacity by an adhesive layer, which has excellent blister resistance and whitening resistance under high-durability conditions.
Technical scheme for solving technical problem
The present inventors have conducted extensive studies to solve the above problems. As a result, the present inventors have found that the above problems can be solved by a laminate having the following structure, and have completed the present invention.
The present invention is, for example, the inventions of [1] to [3] below.
[1] A laminate comprising a first layer and a second layer laminated via an adhesive layer, wherein the second layer is a polycarbonate sheet having a weight ratio of 1.0010 to 1.0050 before and after being left for 72 hours (weight after the left standing/weight before the left standing) in an environment of 85 ℃/85% RH, the adhesive layer is formed from an adhesive composition comprising a (meth) acrylic copolymer (A) and an isocyanate-based crosslinking agent (B), the (meth) acrylic copolymer (A) is a copolymer of monomer components including a polymerizable macromonomer and a crosslinkable functional group-containing monomer, and the isocyanate-based crosslinking agent (B) has an alkyleneoxy group having 2 or more carbon atoms.
[2] The laminate according to [1], wherein the (meth) acrylic copolymer (A) is a copolymer of monomer components comprising 1 to 35 mass% of the polymerizable macromonomer and 0.5 to 20 mass% of the crosslinkable functional group-containing monomer.
[3] A touch panel comprising the laminate according to [1] or [2 ].
ADVANTAGEOUS EFFECTS OF INVENTION
The present invention provides a laminate of a polycarbonate sheet and other layers having high water absorption capacity via an adhesive layer, which is excellent in blister resistance and whitening resistance under high-durability conditions.
Drawings
Fig. 1 is a cross-sectional view schematically showing an example of a touch panel unit in a resistive-film type touch panel.
Fig. 2 is a cross-sectional view schematically showing an example of a touch panel unit in a capacitance type touch panel.
Detailed Description
The following describes in detail embodiments for carrying out the present invention. In the present specification, acrylic acid and methacrylic acid are also collectively referred to as "(meth) acrylic acid".
[ laminate ]
In the laminate of the present invention, the first layer and the second layer are laminated via the adhesive layer. For example, the laminate of the present invention has a first layer, an adhesive layer, and a second layer in this order in the lamination direction.
The second layer is a polycarbonate sheet having a weight ratio (weight after placement/weight before placement) of 1.0010 to 1.0050 before and after 72 hours of placement in an atmosphere of 85 ℃/85% RH. The pressure-sensitive adhesive layer is formed from a pressure-sensitive adhesive composition containing a (meth) acrylic copolymer (A) and an isocyanate-based crosslinking agent (B), wherein the (meth) acrylic copolymer (A) is a copolymer of monomer components including a polymerizable macromonomer and a crosslinkable functional group-containing monomer, and the isocyanate-based crosslinking agent (B) has an alkyleneoxy group having 2 or more carbon atoms.
<First layer>
Examples of the first layer include plastic films such as polyesters (e.g., polyethylene terephthalate (PET) and polyethylene naphthalate (PEN)), Polycarbonates (PC), polymethyl methacrylate (PMMA), polyethylene, polypropylene, polyvinyl chloride, polyurethane, polyamide, acrylonitrile-styrene-butadiene copolymer, and ethylene-vinyl acetate copolymer; a glass plate; a transparent conductive film described later; plastic film with transparent conductive film, and glass plate with transparent conductive film.
The first layer is, for example, a layer constituting a touch panel unit described later.
The first layer is, for example, an optical film including a polarizing plate. As the polarizing plate, a polarizing plate in which an appropriate transparent protective film is laminated on one side or both sides of a polarizer is generally used. Examples of the transparent protective film include cellulose resins, cyclic polyolefin resins, (meth) acrylic resins, phenylmaleimide resins, and polycarbonate resins.
The first layer may be, for example, a substrate derived from an adhesive sheet having the substrate and an adhesive layer formed on one surface of the substrate. The substrate may be the above plastic film. The pressure-sensitive adhesive layer is formed from the pressure-sensitive adhesive composition containing a (meth) acrylic copolymer (a) and an isocyanate-based crosslinking agent (B) having an alkyleneoxy group having 2 or more carbon atoms.
The thickness of the first layer is usually 5 to 1000. mu.m, preferably 10 to 500. mu.m.
<Second layer>
The second layer is a polycarbonate sheet (hereinafter also referred to as "PC sheet").
The weight ratio of the PC board before and after being left for 72 hours in an environment of 85 ℃/85% RH (the weight after the left/the weight before the left) is 1.0010 to 1.0050, preferably 1.0015 to 1.0040, and more preferably 1.0018 to 1.0035. The above weight ratio is a value determined according to the following definition. The PC board was left to stand at 85 ℃ for 72 hours in a dry environment, and the weight thereof (weight 1: weight before standing in a moist heat environment) was measured immediately after taking out from the above environment. Thereafter, the PC board was left to stand at 85 ℃ C/85% RH for 72 hours, and immediately after taking out from the above-mentioned environment, the weight thereof (weight 2: weight after leaving in a moist heat environment) was measured. The weight ratio (weight 2/weight 1) was calculated from the weights 1 and 2 before and after the introduction of the 85 ℃/85% RH atmosphere.
In the conventional laminate, if the water absorption capacity of the PC board is low and the weight ratio is less than 1.0010, no problem is found in the durability test, but if the water absorption capacity of the PC board is high and the weight ratio is 1.0010 or more, foaming or whitening may occur in the durability test. In the laminate of the present invention, even if the weight ratio of the PC board is 1.0010 or more, the blister resistance and the whitening resistance are excellent. This is because the pressure-sensitive adhesive layer constituting the laminate of the present invention easily absorbs moisture and has high elasticity enough to suppress the occurrence of the foaming phenomenon.
The density of the PC board is usually 1.000 to 1.120g/cm3Preferably 1.050 to 1.110g/cm3More preferably 1.080 to 1.100g/cm3. In the conventional laminate, if the density of the PC board exceeds 1.120g/cm3There is no problem in the durability test, but if the density is 1.120g/cm3The following is in the durability testSometimes blistering or whitening occurs. In the laminate of the present invention, the density of the PC board is 1.120g/cm3Hereinafter, the occurrence of foaming, whitening, and the like in the durability test can also be suppressed.
The second layer is, for example, a PC board as a transparent member constituting a touch panel unit described later. The second layer is, for example, a PC board to which an optical film is attached via the adhesive layer.
The thickness of the PC board is usually 0.3 to 3mm, preferably 0.5 to 2 mm.
<Adhesive layer>
The pressure-sensitive adhesive layer is formed from the above-mentioned pressure-sensitive adhesive composition containing a (meth) acrylic copolymer (a) described below and an isocyanate-based crosslinking agent (B) having an alkyleneoxy group having 2 or more carbon atoms (hereinafter, simply referred to as "isocyanate-based crosslinking agent (B)").
By using the adhesive composition, an adhesive layer having blister resistance and whitening resistance even under high-durability conditions and having good adhesion to the first and second layers can be formed.
(meth) acrylic copolymer (A)
The (meth) acrylic copolymer (a) is a copolymer of monomer components including a polymerizable macromonomer and a crosslinkable functional group-containing monomer, and can be obtained by copolymerizing the monomer components. The monomer component is generally a monomer containing a polymerizable unsaturated group.
<Polymerizable macromonomer>
The monomer component contains a polymerizable macromonomer.
The polymerizable macromonomer has a polymerizable unsaturated group. Examples of the polymerizable unsaturated group include an ethylenically unsaturated double bond. For example, the polymer may have a (meth) acryloyl group at the end.
In the polymerization of the monomer component, the polymerizable macromonomer is incorporated into the (meth) acrylic copolymer (a) by, for example, a radical polymerization reaction with the other monomer forming the (meth) acrylic copolymer (a) among the polymerizable unsaturated groups. When regarded as the (meth) acrylic copolymer (a), a side chain based on the polymerizable macromonomer is formed. The side chains prevent the molecules of the (meth) acrylic copolymer (A) from being concentrated with each other.
The polymerizable macromonomer is, for example, a polymer having a weight average molecular weight (Mw) of usually 500 to 10 ten thousand, preferably 1000 to 5 ten thousand. The weight average molecular weight (Mw) of the polymerizable macromonomer in the present specification means a weight average molecular weight in terms of standard polystyrene measured by a Gel Permeation Chromatography (GPC) method.
The glass transition temperature (Tg) of the polymerizable macromonomer is preferably 50 to 180 ℃, more preferably 80 to 150 ℃. Therefore, the (meth) acrylic copolymer (a) is hard from the viewpoint of Tg, and the resultant pressure-sensitive adhesive layer is excellent in blister resistance. The Tg of the polymerizable macromonomer can be determined by the formula of Fox, and when a commercially available product is used, the Tg can be determined by a value described in a manual.
Examples of the monomer constituting the polymer chain (main chain) portion of the polymerizable macromonomer include alkyl (meth) acrylates such as methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, and t-butyl (meth) acrylate, the alkyl group preferably having 1 to 20 carbon atoms, styrene monomers such as (meth) acrylonitrile, (styrene), and α -methylstyrene, and one kind of the monomer may be used alone or two or more kinds may be used.
The polymerizable macromonomer is preferably a (meth) acrylic macromonomer, a (meth) acrylonitrile macromonomer, or a styrene macromonomer, and can be produced by various known methods, for example, a method described in paragraph [0039] of Japanese patent laid-open No. 2013-018227.
Examples of the polymerizable macromonomer that can be used include commercially available ones, for example, a macromonomer in which a main chain constituting monomer is methyl methacrylate (product name: 45% AA-6(AA-6S), AA-6; manufactured by Toyo Synthesis Co., Ltd., manufactured by Bay, Ltd.), a macromonomer in which a main chain is a copolymer of styrene/acrylonitrile (product name: AN-6S; manufactured by Toyo Synthesis Co., Ltd.), and a macromonomer in which a main chain constituting monomer is butyl acrylate (product name: AB-6; manufactured by Toyo Synthesis Co., Ltd.), and the terminals of these are methacryloyl groups.
The polymerizable macromonomer may be used alone or in combination of two or more.
The amount of the polymerizable macromonomer in the whole monomer components is usually 1 to 35% by mass, preferably 2 to 33% by mass, more preferably 5 to 30% by mass. The amount of the structural unit derived from the polymerizable macromonomer is preferably within the above range described in this paragraph, out of all the structural units derived from the monomer. When the amount of the polymerizable macromonomer is within the above range, expansion of foaming at the interface between the first and second layers and the pressure-sensitive adhesive layer is suppressed, and therefore, blister resistance is excellent and adhesion between these layers is excellent. The amount of the above-mentioned structural unit can be calculated from the amount of the monomer charged, for example, and is the same in other examples.
<Monomer having crosslinkable functional group>
The monomer component contains a monomer having a crosslinkable functional group.
The crosslinkable group is a functional group which can be crosslinked with the isocyanate crosslinking agent (B), and examples thereof include a hydroxyl group and an acid group. Examples of the monomer having a crosslinkable functional group include a hydroxyl group-containing monomer and an acid group-containing monomer, and among these, a hydroxyl group-containing monomer is preferable.
Examples of the hydroxyl group-containing monomer include hydroxyl group-containing (meth) acrylates, and specific examples thereof include hydroxyalkyl (meth) acrylates such as 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, and 8-hydroxyoctyl (meth) acrylate.
Examples of the carboxyl group-containing monomer include carboxyl group-containing (meth) acrylates such as β -carboxyethyl (meth) acrylate, 5-carboxypentyl (meth) acrylate, succinic acid mono (meth) acryloyloxyethyl ester, and ω -carboxypolycaprolacton mono (meth) acrylate, (meth) acrylic acid, itaconic acid, crotonic acid, fumaric acid, and maleic acid.
In one embodiment, when corrosion due to an acid group of a layer in contact with the pressure-sensitive adhesive layer is a problem, for example, when the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition is in direct contact with a wiring made of a metal or a metal oxide, it is preferable that a monomer containing an acid group is not substantially used, that is, the (meth) acrylic copolymer (a) does not substantially contain the acid group. The fact that the acid group is not substantially contained means that the acid value of the (meth) acrylic copolymer (A) is 0.5mgKOH/g or less, for example.
Among the monomers having a crosslinkable functional group, a hydroxyl group-containing monomer is preferable. At least a part of the hydroxyl groups derived from the hydroxyl group-containing monomer serve as crosslinking points in the (meth) acrylic copolymer (a), and can form a crosslinked structure, for example, by reacting with isocyanate groups of the isocyanate-based crosslinking agent (B).
One monomer having a crosslinkable functional group may be used alone, or two or more monomers may be used.
The amount of the crosslinkable functional group-containing monomer in the whole monomer components is usually 0.5 to 20% by mass, preferably 1.5 to 15% by mass, and more preferably 2 to 13% by mass. The amount of the structural unit derived from the crosslinkable functional group-containing monomer is preferably within the above range described in this paragraph, among all the structural units derived from the monomer. In such a form, the crosslinked structure of the (meth) acrylic copolymer (a) is appropriately formed, and a pressure-sensitive adhesive layer having appropriate flexibility can be obtained.
<Alkoxyalkyl (meth) acrylates>
The monomer component preferably contains an alkoxyalkyl (meth) acrylate. By using the copolymer containing a structural unit derived from an alkoxyalkyl (meth) acrylate, moisture absorbed in the adhesive layer can be dispersed in the adhesive layer under a high-humidity environment, and blister resistance and whitening resistance can be improved.
The number of carbon atoms of the alkoxyalkyl group in the alkoxyalkyl (meth) acrylate is usually 2 to 18, preferably 2 to 12, and more preferably 2 to 10. Examples of the alkoxyalkyl (meth) acrylate include methoxymethyl (meth) acrylate, 2-methoxyethyl (meth) acrylate, 2-ethoxyethyl (meth) acrylate, 3-methoxypropyl (meth) acrylate, 3-ethoxypropyl (meth) acrylate, 4-methoxybutyl (meth) acrylate, and 4-ethoxybutyl (meth) acrylate.
The alkoxyalkyl (meth) acrylate may be used alone or in combination of two or more.
The amount of the alkoxyalkyl (meth) acrylate in the entire monomer components is usually 50 to 98 mass%, preferably 55 to 95 mass%, and more preferably 60 to 90 mass%. The amount of the structural unit derived from the alkoxyalkyl (meth) acrylate is preferably within the above range described in this paragraph, among all the structural units derived from the monomer. If the amount of the alkoxyalkyl (meth) acrylate is not less than the lower limit, the alkoxy group is hydrophilic, and thus the blister resistance and whitening resistance are increased by dispersing moisture penetrating into the pressure-sensitive adhesive layer; if the upper limit or less is not more than the above upper limit, the first and second layers have excellent adhesion to the pressure-sensitive adhesive layer.
<Other monomers>
The monomer component may further contain other monomers than the above-mentioned monomers. Examples of the monomer other than the above monomers include alkyl (meth) acrylates, (meth) acrylates having an alicyclic hydrocarbon group or an aromatic hydrocarbon group, alkoxy polyalkylene glycol mono (meth) acrylates, styrene monomers, amide group-containing monomers, amino group-containing monomers, cyano group-containing monomers, and vinyl acetate.
The number of carbon atoms of the alkyl group in the alkyl (meth) acrylate is preferably 1 to 20. Examples of the alkyl (meth) acrylate include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, t-butyl (meth) acrylate, pentyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, isooctyl (meth) acrylate, nonyl (meth) acrylate, isononyl (meth) acrylate, decyl (meth) acrylate, isodecyl (meth) acrylate, undecyl (meth) acrylate, lauryl (meth) acrylate, oleyl (meth) acrylate, n-stearyl (meth) acrylate, isostearyl (meth) acrylate, isopropyl (meth) acrylate, eicosyl (meth) acrylate (Japanese: ジデカ (メタ) アクリレート).
Examples of the (meth) acrylate containing an alicyclic hydrocarbon group or an aromatic hydrocarbon group include cyclohexyl (meth) acrylate, isobornyl (meth) acrylate, adamantyl (meth) acrylate, benzyl (meth) acrylate, phenyl (meth) acrylate, and phenoxyethyl (meth) acrylate.
Examples of the alkoxy polyalkylene glycol mono (meth) acrylate include methoxy diethylene glycol mono (meth) acrylate, methoxy dipropylene glycol mono (meth) acrylate, ethoxy triethylene glycol mono (meth) acrylate, ethoxy diethylene glycol mono (meth) acrylate, and methoxy triethylene glycol mono (meth) acrylate.
Examples of the styrene-based monomer include styrene; alkylstyrenes such as methylstyrene, dimethylstyrene, trimethylstyrene, propylstyrene, butylstyrene, hexylstyrene, heptylstyrene, octylstyrene, and the like; halogenated styrenes such as fluorostyrene, chlorostyrene, bromostyrene, dibromostyrene, etc.; functionalized styrenes such as nitrostyrene, acetyl styrene, and methoxy styrene.
Examples of the amide group-containing monomer include N-alkyl (meth) acrylamides such as (meth) acrylamide, N-methyl (meth) acrylamide, N-ethyl (meth) acrylamide, N-propyl (meth) acrylamide and N-hexyl (meth) acrylamide, N, N-dimethyl (meth) acrylamide, and N, N-dialkyl (meth) acrylamides such as N, N-diethyl (meth) acrylamide; nitrogen heterocyclic ring-containing monomers such as N-vinylpyrrolidone, N-vinylcaprolactam and (meth) acryloylmorpholine.
Examples of the amino group-containing monomer include N, N-dialkylaminoalkyl (meth) acrylates such as N, N-dimethylaminoethyl (meth) acrylate and N, N-diethylaminoethyl (meth) acrylate.
Examples of the cyano group-containing monomer include cyano (meth) acrylate and (meth) acrylonitrile.
One of the other monomers may be used alone, or two or more of them may be used.
The amount of other monomers in the total monomer components is preferably 35% by mass or less. The amount of the structural unit derived from another monomer is preferably 35% by mass or less of the total structural units derived from the monomers.
<Constitution of (meth) acrylic copolymer (A) and production method>
The weight average molecular weight (Mw) of the (meth) acrylic copolymer (a) as measured by a Gel Permeation Chromatography (GPC) method is usually 10 to 80 ten thousand, preferably 15 to 60 ten thousand, and more preferably 20 to 50 ten thousand. In such a form, a pressure-sensitive adhesive layer having excellent high-temperature durability can be obtained.
The molecular weight distribution (Mw/Mn; Mn is the number average molecular weight) of the (meth) acrylic copolymer (A) is usually 1.5 to 15, preferably 2 to 13, more preferably 5 to 12. In such a form, a pressure-sensitive adhesive layer having excellent high-temperature durability can be obtained.
Mw and Mw/Mn can be measured, for example, by the methods described in examples.
The glass transition temperature (Tg) of the (meth) acrylic copolymer (A) as determined by the so-called Fox formula is usually-80 to 0 ℃ and preferably-70 to-10 ℃. In this form, an adhesive layer having excellent adhesive strength at room temperature (25 ℃ C.) can be obtained. If Tg is too high, compatibility of the pressure-sensitive adhesive layer with the first and second layers is deteriorated, and defects such as foaming and wrinkles are likely to occur.
The glass transition temperature (Tg) of the homopolymer formed from each monomer in the formula of Fox can be, for example, a value described in Polymer handbook, fourth edition (Wiley-Interscience 2003).
The total content of the (meth) acrylic copolymer (a) and the isocyanate-based crosslinking agent (B) in the pressure-sensitive adhesive composition is usually 70% by mass or more, preferably 75% by mass or more, and more preferably 80% by mass or more, based on 100% by mass of the solid content of the pressure-sensitive adhesive composition. The solid component means a component other than the solvent.
The (meth) acrylic copolymer (a) can be produced by a known method, but is preferably produced by solution polymerization. Specifically, a monomer component and a polymerization solvent are charged into a reaction vessel, a polymerization initiator is added under an inert gas atmosphere such as nitrogen, and the reaction is heated to about 50 to 90 ℃ to react for 2 to 20 hours. In addition, a polymerization initiator, a chain transfer agent, a monomer component, and a polymerization solvent may be added to the polymerization reaction as appropriate.
The polymerization initiator may, for example, be a conventional organic polymerization initiator, and specifically, may, for example, be a peroxide such as benzoyl peroxide or lauroyl peroxide, or an azo compound such as 2,2' -azobisisobutyronitrile. Among them, azo compounds are preferred.
Examples of the azo compound include 2,2 '-azobisisobutyronitrile, 2' -azobis (4-methoxy-2, 4-dimethylvaleronitrile), 2 '-azobis (2-cyclopropylpropionitrile), 2' -azobis (2, 4-dimethylvaleronitrile), 2 '-azobis (2-methylbutyronitrile), 1' -azobis (cyclohexane-1-carbonitrile), 2- (carbamoylazo) isobutyronitrile, 2-phenylazo-4-methoxy-2, 4-dimethylvaleronitrile, 2 '-azobis (2-amidinopropane) dihydrochloride, 2' -azobis (N, N '-dimethyleneisobutylamidine), 2' -azobis [ 2-methyl-N- (2-hydroxyethyl) -propionamide ], 2' -azobis (isobutyramide) dihydrate, 4 ' -azobis (4-cyanovaleric acid), 2' -azobis (2-cyanopropanol), dimethyl 2,2' -azobis (2-methylpropionate), 2' -azobis [ 2-methyl-N- (2-hydroxyethyl) propionamide ].
One kind of the polymerization initiator may be used alone, or two or more kinds may be used.
The amount of the polymerization initiator used is usually 0.01 to 5 parts by mass per 100 parts by mass of the monomer component. In such a form, the Mw of the (meth) acrylic copolymer (A) can be adjusted within an appropriate range.
In the solution polymerization, the polymerization solvent may, for example, be an aromatic hydrocarbon such as benzene, toluene or xylene; aliphatic hydrocarbons such as n-pentane, n-hexane, n-heptane, and n-octane; alicyclic hydrocarbons such as cyclopentane, cyclohexane, cycloheptane, and cyclooctane; diethyl ether, diisopropyl ether, 1, 2-dimethoxyethane, dibutyl ether, tetrahydrofuran and dibutyl ether
Ethers such as alkyl, anisole, phenetole, and diphenyl ether; halogenated hydrocarbons such as chloroform, carbon tetrachloride, 1, 2-dichloroethane, chlorobenzene, and the like; esters such as ethyl acetate, propyl acetate, butyl acetate, and methyl propionate; ketones such as acetone, methyl ethyl ketone, diethyl ketone, methyl isobutyl ketone, and cyclohexanone; amides such as N, N-dimethylformamide, N-dimethylacetamide and N-methylpyrrolidone; nitriles such as acetonitrile and benzonitrile; sulfoxides such as dimethyl sulfoxide and sulfolane.
One kind of the polymerization solvent may be used alone, or two or more kinds thereof may be used.
Cross-linking agent of isocyanate type (B)
The isocyanate-based crosslinking agent (B) is a component capable of initiating a crosslinking reaction with the (meth) acrylic copolymer (A). The isocyanate-based crosslinking agent (B) is, for example, an isocyanate compound having 2 or more isocyanate groups (-N ═ C ═ O) in 1 molecule. The number of isocyanate groups in 1 molecule is preferably 2 to 8, more preferably 2 to 6.
The isocyanate-based crosslinking agent (B) has an alkyleneoxy group having 2 or more carbon atoms. Here, "alkyleneoxy" means a 2-valent group represented by-R-O-, wherein R is an alkanediyl group having 2 or more carbon atoms. The upper limit of the carbon number of the alkyleneoxy group is usually 10, preferably 8.
In addition, the reactant of toluene diisocyanate and trimethylolpropane, for example, although having-CH2-O-, but not having carbonAn alkyleneoxy group (a 2-valent group) having a number of 2 or more.
The alkyleneoxy group having 2 or more carbon atoms may be contained in the crosslinking agent (B) as a part of the ring-opening structure of the lactone as in the formula (3) described later, or may be contained as in the formula (4) described later. For example, the isocyanate-based crosslinking agent having a lactone-modified group and/or an alkylene oxide-modified group is preferable, and examples thereof include compounds having a structure in which a polyfunctional isocyanate compound having 2 or more molecules bonded to a urethane group is included in a compound obtained by modifying a polyol with a lactone and/or an alkylene oxide. The lactone-modifying group means a ring-opened structure of a lactone, and the alkylene oxide-modifying group means a ring-opened structure of an alkylene oxide.
Since the isocyanate-based crosslinking agent (B) has an alkyleneoxy group having 2 or more carbon atoms, the distance between crosslinking points becomes long. In general, in order to improve durability, the compatibility with a substrate or an adherend of the pressure-sensitive adhesive layer tends to be reduced by hardening the polymer component, but by using the crosslinking agent (B) having a long distance between crosslinking points, flexibility is imparted to the pressure-sensitive adhesive layer, and the compatibility is improved, whereby a pressure-sensitive adhesive layer having both hardness and flexibility can be obtained. That is, in the present invention, the durability of the pressure-sensitive adhesive layer can be improved by hardening the (meth) acrylic copolymer (a), and the deterioration of the compatibility with the first and second layers accompanying the hardening of the copolymer (a) can be prevented by using the crosslinking agent (B) having a long distance between crosslinking points. Therefore, even when a polycarbonate sheet having high water absorption capacity is used, a laminate having good durability (blister resistance) can be obtained.
Examples of the polyhydric alcohol include alcohols having a valence of 3 or more such as trimethylolpropane, glycerol and pentaerythritol. The number of hydroxyl groups in the polyol is preferably 3 to 8.
Examples of the lactone include β -propiolactone, γ -butyrolactone, δ -valerolactone, and ∈ -caprolactone cyclic esters having 3 to 11 carbon atoms, and examples of the alkylene oxide include ethylene oxide, propylene oxide, and butylene oxide having 2 to 10 carbon atoms.
Examples of the polyfunctional isocyanate compound include aliphatic diisocyanates and alicyclic diisocyanates, and isocyanurate bodies and biuret bodies thereof. Examples of the aliphatic diisocyanate include aliphatic diisocyanates having 4 to 30 carbon atoms such as ethylene diisocyanate, tetramethylene diisocyanate, pentamethylene diisocyanate, hexamethylene diisocyanate, 2-methyl-1, 5-pentamethylene diisocyanate, 3-methyl-1, 5-pentamethylene diisocyanate, and 2,2, 4-trimethyl-1, 6-hexamethylene diisocyanate. Examples of the alicyclic diisocyanate include alicyclic diisocyanates having 7 to 30 carbon atoms such as isophorone diisocyanate, cyclopentyl diisocyanate, cyclohexyl diisocyanate, hydrogenated xylylene diisocyanate, hydrogenated tolylene diisocyanate, hydrogenated diphenylmethane diisocyanate, and hydrogenated tetramethylxylylene diisocyanate.
The isocyanate-based crosslinking agent (B) preferably has a skeleton derived from trimethylolpropane ((-O-CH)2-)3-C-CH2CH3) The crosslinking agent of (3) is more preferably a crosslinking agent represented by the formula (1) or (2).
[ solution 1]
In the formulae (1) and (2), R1A、R1BAnd R1CEach independently is a group containing a group represented by the formula (3) and/or a group represented by the formula (4), R2A、R2B、R2C、R3A、R3B、R3C、R3D、R3EAnd R3FIndependently represents an alkanediyl group having 4 to 10 carbon atoms such as 1, 6-hexanediyl group.
[ solution 2]
In the formula (3), R11Is a C2-10, preferably C4-8 alkanediyl group, more preferably a straight chain, and m is an integer of 1-10, preferably an integer of 1-6. In the formula (4), R21N is an alkanediyl group having 2 to 10 carbon atoms, preferably 4 to 8 carbon atomsIs an integer of 1 to 10, preferably an integer of 1 to 6.
Examples of the group containing the group represented by formula (3) and/or the group represented by formula (4) include a group represented by formula (3), a group represented by formula (4), a group represented by formula (3), and a group represented by formula (4).
From the viewpoint of further improving the elasticity of the pressure-sensitive adhesive layer, the molecular weight of the isocyanate-based crosslinking agent (B) is preferably 500 to 10000, more preferably 1500 to 7000.
As the isocyanate-based crosslinking agent (B), a commercially available crosslinking agent can be used. Examples thereof include E402-80B (manufactured by Asahi Kasei corporation), E405-70B (manufactured by Asahi Kasei corporation) and MFA-75B (manufactured by Asahi Kasei corporation).
The isocyanate-based crosslinking agent (B) may be used alone or in combination of two or more.
The content of the isocyanate-based crosslinking agent (B) in the adhesive composition is usually 0.01 to 5 parts by mass, preferably 0.05 to 3 parts by mass, and more preferably 0.1 to 2.5 parts by mass, based on 100 parts by mass of the (meth) acrylic copolymer (a). In such a form, a crosslinked structure can be sufficiently and appropriately formed, and a pressure-sensitive adhesive layer having high cohesive force and excellent durability can be obtained.
Other crosslinking Agents
The adhesive composition may contain other crosslinking agents such as a metal chelate crosslinking agent and/or an epoxy crosslinking agent in addition to the isocyanate crosslinking agent (B).
In the pressure-sensitive adhesive composition, the content of the other crosslinking agent is preferably 5 parts by mass or less, and more preferably 3 parts by mass or less, per 100 parts by mass of the (meth) acrylic copolymer (a). In such a form, a crosslinked structure can be sufficiently and appropriately formed, and a pressure-sensitive adhesive layer having a high cohesive force, an excellent balance of adhesive properties, and excellent durability can be obtained.
Examples of the metal chelate crosslinking agent include compounds obtained by coordinating a polyvalent metal such as aluminum, iron, copper, zinc, tin, titanium, nickel, antimony, magnesium, vanadium, chromium, or zirconium with an alkoxide, acetylacetone, or ethyl acetoacetate. Specifically, it may, for example, be aluminum isopropoxide, aluminum sec-butoxide, aluminum ethyl acetoacetate diisopropyl ester, aluminum triethyl acetoacetate or aluminum triacetylacetonate.
As the epoxy crosslinking agent, an epoxy compound having 2 or more epoxy groups in 1 molecule is generally used. For example, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, glycerol triglycidyl ether, 1, 3-bis (N, N-diglycidylaminomethyl) cyclohexane, N '-tetraglycidyl m-xylylenediamine, N' -tetraglycidylaminophenylmethane, triglycidyl isocyanurate, m-N, N-diglycidylaminophenylglycidyl ether, N-diglycidyltoluidine, N-diglycidylaniline may be mentioned.
(plasticizers)
In one embodiment, the adhesive composition preferably further contains a plasticizer.
Examples of the plasticizer include phthalate compounds, adipate compounds, trimellitate compounds, sebacate compounds, citrate compounds, phosphate compounds, polyester compounds, palmitic acid compounds and stearic acid compounds, and specific examples thereof include dioctyl phthalate, diisononyl phthalate, diisodecyl phthalate, dibutyl phthalate, dioctyl adipate, diisononyl adipate, trioctyl trimellitate, tricresyl phosphate, low molecular weight polyesters, isopropyl palmitate, octyl palmitate, methyl stearate, butyl stearate and octyl stearate. Among them, palmitic acid compounds and/or stearic acid compounds are preferable from the viewpoint of compatibility with the (meth) acrylic copolymer (a).
One kind of the plasticizer may be used alone, or two or more kinds thereof may be used.
The content of the plasticizer in the adhesive composition is usually 0.01 to 3 parts by mass, preferably 0.05 to 1 part by mass, based on 100 parts by mass of the (meth) acrylic copolymer (a). In this form, the compatibility with an adherend (PC board) is excellent.
Additives for food
The pressure-sensitive adhesive composition may contain, in addition to the above components, at least 1 selected from the group consisting of a silane coupling agent, an antistatic agent, an ultraviolet absorber, an antioxidant, a resin for imparting adhesiveness, an adhesive force modifier (for example, an organopolysiloxane compound), an antifoaming agent, a filler, a stabilizer, a softening agent, and a wettability modifier, within a range not to impair the effects of the present invention.
Organic solvent
The adhesive composition may contain an organic solvent for the purpose of improving the workability.
The organic solvent may, for example, be the polymerization solvent described in the description of the process for producing the (meth) acrylic copolymer (a). For example, an adhesive composition can be prepared by mixing a solution containing the (meth) acrylic copolymer (a) and a polymerization solvent with the isocyanate-based crosslinking agent (B). The content of the organic solvent in the adhesive composition is usually 0 to 90% by mass, preferably 10 to 80% by mass.
Formation of adhesive layer
The pressure-sensitive adhesive layer can be obtained by crosslinking the pressure-sensitive adhesive composition, specifically by crosslinking the acrylic copolymer (a) in the isocyanate-based crosslinking agent (B) (meth).
The conditions for forming the adhesive layer are, for example, as follows. The adhesive composition is applied to the first spacer and dried at 60 to 120 ℃ and preferably 70 to 110 ℃ for 1 to 5 minutes and preferably 2 to 4 minutes to form a coating film. Next, a second spacer is bonded to the coating film. Then, the obtained laminate is cured (aged) in an atmosphere of usually 5 to 60 ℃, preferably 15 to 40 ℃, usually 30 to 70% RH, preferably 40 to 70% RH for usually 1 day or more, preferably 3 to 10 days. When crosslinking is carried out under such a curing condition, the crosslinked material can be efficiently formed.
The spacer is preferably a spacer obtained by peeling a long base material on one side or both sides, and examples of the base material include plastics such as polyester (e.g., polyethylene terephthalate, polyethylene naphthalate), polycarbonate, polymethyl methacrylate, polyethylene, polypropylene, polyvinyl chloride, polyurethane, polyamide, and ethylene-vinyl acetate copolymer; non-woven fabrics; paper.
The thickness of the adhesive layer is usually 3 to 1000. mu.m, preferably 5 to 500. mu.m.
The gel fraction of the adhesive layer is preferably 40 to 95 mass%, more preferably 50 to 90 mass%, and still more preferably 60 to 85 mass%. Such a form is preferable from the viewpoint of improvement of the cohesive force and the adhesive force.
The gel fraction can be determined as follows. About 0.1g of the adhesive was collected from the adhesive layer and put into a sample bottle, and after adding 30mL of ethyl acetate and shaking for 4 hours, the content of the sample bottle was filtered through a 200-mesh stainless steel wire net, and the residue on the wire net was dried at 100 ℃ for 2 hours to measure the dried mass. The gel fraction of the adhesive layer was determined by the following formula.
Gel fraction (% by mass) × 100 (%)
The pressure-sensitive adhesive layer is disposed for bonding the first layer and the second layer, for example, for bonding a transparent member (i.e., the first and second layers are transparent members) described later or bonding a transparent member and a transparent conductive film (i.e., the first layer is a transparent conductive film and the second layer is a transparent member) described later to each other.
<Production of laminate>
The laminate of the present invention can be obtained by bonding the first layer and the second layer with the adhesive layer obtained from the adhesive composition. For example, the first layer and the second layer can be attached to each other by attaching a surface of the adhesive layer to a surface of the first layer (or the second layer) and then attaching the other surface (inner surface) of the adhesive layer to a surface of the second layer (or the first layer).
The laminate of the present invention can also be obtained by using an adhesive sheet having a substrate as a first layer and an adhesive layer formed on one surface of the substrate and made of the adhesive composition, and bonding the adhesive layer to a polycarbonate plate as a second layer.
[ use of touch Screen ]
The touch panel is mounted on, for example, a smartphone or a tablet computer, and is also mounted on a vehicle-mounted device such as a car navigation system device. The touch screen comprises a touch screen unit.
Examples of the touch panel unit include a resistive type touch panel unit and a capacitive type touch panel unit, and these are laminates of various materials, and the laminate of the present invention can be used as a part or all of the units.
The touch panel unit is disposed on the outermost surface of the screen, and is required to have high transparency for the adhesive used, and also to have high heat resistance, moist heat resistance, and the like.
The touch panel unit includes, for example, a surface support, an adhesive layer, and a transparent conductive film made of a metal or a metal oxide in this order in the stacking direction, or includes a surface support, an adhesive layer, an electrode support, and a transparent conductive film made of a metal or a metal oxide in this order in the stacking direction. Examples of the metal and metal oxide include Indium Tin Oxide (ITO), Antimony Tin Oxide (ATO), and tin oxide.
<Resistive film type touch panel>
As shown in fig. 1, the resistive touch panel unit 10-1 is formed by bonding an upper laminate 11-1 and a lower laminate 13-1 so as to form a gap 34 with a bonding agent 30, and a spacer 32 is disposed in the gap 34 so as to effectively secure the gap width.
Transparent conductive films 27-1 and 27-2 made of metal or metal oxide are disposed in the upper laminate 11-1 and the lower laminate 13-1, respectively, so as to face the gap 34. The transparent conductive films 27-1 and 27-2 are usually formed on the surfaces of the upper electrode support 25-1 and the lower electrode support 25-2, which are transparent members.
A surface support 21-1 is disposed on the outermost surface of the upper laminate 11-1, and the surface support 21-1 is usually a transparent member. A deep surface support 21-2 is disposed in the deepest portion of the lower laminated body 13-1 so as to face the surface of a Flat Panel Display (FPD), and the surface support 21-2 is usually a transparent member. The pressure-sensitive adhesive layer 23-1 is disposed so as to adhere the surface support 21-1 and the upper electrode support 25-1. The pressure-sensitive adhesive layer 23-2 is disposed so as to adhere the surface support 21-2 and the lower electrode support 25-2 in the deep portion.
Examples of the transparent member include transparent plastic films such as polyesters (e.g., polyethylene terephthalate, polyethylene naphthalate), polycarbonates, and polymethyl methacrylates; a glass plate. This is also the same in the capacitance method described below.
As a laminate of the surface support 21-1, the pressure-sensitive adhesive layer 23-1 and the upper electrode support 25-1, the laminate of the present invention can be used. In this case, the pressure-sensitive adhesive layer 23-1 is formed by the pressure-sensitive adhesive composition, and at least one of the surface support 21-1 and the upper electrode support 25-1 is a polycarbonate plate having the above weight ratio of 1.0010 to 1.0050.
Further, as a laminate of the deep surface support 21-2, the pressure-sensitive adhesive layer 23-2 and the lower electrode support 25-2, the laminate of the present invention can be used. In this case, the pressure-sensitive adhesive layer 23-2 is formed by the pressure-sensitive adhesive composition, and at least one of the deep surface support 21-2 and the lower electrode support 25-2 is a polycarbonate plate having the above weight ratio of 1.0010 to 1.0050.
The transparent conductive films 27-1 and 27-2 form a circuit, and when pressure is applied from above the surface support 21-1 by a finger or the like, the gap 34 of the portion to which the pressure is applied disappears, and the transparent conductive films 27-1 and 27-2 are energized in contact, and the pressurized portion can be detected.
<Capacitive touch panel>
As shown in fig. 2, a capacitive touch panel unit 10-2 generally has a structure in which a central support 60 made of a transparent member is sandwiched and an upper laminate 15-1 and a lower laminate 15-2 are disposed.
In the upper laminate 15-1, the transparent conductive film 57-1 is disposed in contact with the central support 60, and the surface support 51-1 made of a transparent member is disposed on the outermost surface. The adhesive layer 53-1 is disposed so as to adhere the transparent conductive film 57-1 to the surface support 51-1, and the adhesive layer 53-1 is in direct contact with the transparent conductive film 57-1.
As the upper laminate 15-1, the laminate of the present invention can be used. In this case, the adhesive layer 53-1 is formed by the adhesive composition described above, the transparent conductive film 57-1 is a first layer, and the surface support 51-1 is a polycarbonate plate (second layer) having the above weight ratio of 1.0010 to 1.0050.
In the lower laminate 15-2, the transparent conductive film 57-2 is disposed in contact with the central support 60, and the surface support 51-2 made of a transparent member is disposed at the deepest portion. The pressure-sensitive adhesive layer 53-2 is disposed so as to adhere the transparent conductive film 57-2 to the surface support 51-2 in the deepest portion, and the pressure-sensitive adhesive layer 53-2 is in direct contact with the transparent conductive film 57-2.
As the upper laminate 15-2, the laminate of the present invention can be used. In this case, the pressure-sensitive adhesive layer 53-2 is formed by the pressure-sensitive adhesive composition, the transparent conductive film 57-2 is a first layer, and the deepest surface support 51-2 is a polycarbonate plate (second layer) having the above weight ratio of 1.0010 to 1.0050.
In the capacitive touch panel unit 10-2, the deepest surface support 51-2 is disposed so as to face the flat panel display.
The transparent conductive films 57-1 and 57-2 form a circuit. In the capacitive touch panel, a change in the electrostatic capacitance of a contact portion where a finger is in contact with the surface of the touch panel unit 10-2 is read, and a contact position can be detected.
Examples
The present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples. In the following description of examples and the like, "part" means "part by mass" unless otherwise specified.
The measured values in the examples were obtained by the following methods.
[ weight average molecular weight (Mw) and molecular weight distribution (Mw/Mn) ]
For the (meth) acrylic acid-based copolymer, Mw and Mw/Mn in terms of standard polystyrene were determined by a Gel Permeation Chromatography (GPC) method under the following conditions.
The measurement device: HLC-8120GPC (manufactured by Tosoh corporation)
GPC column composition: the following 5 columns (all made by Tosoh corporation)
(1) TSK-GEL HXL-H (guard column)
(2)TSK-GEL G7000HXL
(3)TSK-GEL GMHXL
(4)TSK-GEL GMHXL
(5)TSK-GEL G2500HXL
Sample concentration: diluted with tetrahydrofuran to 1.0mg/cm3
Mobile phase solvent: tetrahydrofuran (THF)
Flow rate: 1.0cm3Minute/min
Column temperature: 40 deg.C
[ glass transition temperature (Tg) ]
The Tg of the (meth) acrylic copolymer is determined by the formula Fox.
Synthesis example 1]
In a reaction apparatus equipped with a stirrer, a reflux condenser, a thermometer and a nitrogen introduction tube, 80 parts of 2-methoxyethyl acrylate (MEA), 10 parts of 2-hydroxyethyl acrylate (HEA), 10 parts of a methyl methacrylate macromonomer (AA-6), 50 parts of methyl ethyl ketone and 80 parts of ethyl acetate were introduced as a solvent, and the temperature was raised to 75 ℃. Then, 0.1 part of 2,2' -azobisisobutyronitrile was added to conduct polymerization at 75 ℃ for 4 hours under a nitrogen atmosphere. After the reaction, the reaction solution was diluted with ethyl acetate to prepare a polymer solution. The obtained (meth) acrylic copolymer (A-1) had Mw of 36 ten thousand, Mw/Mn of 11 and Tg of-37 ℃.
[ Synthesis examples 2 to 8]
(meth) acrylic copolymers (A-2) to (A-8) were synthesized in the same manner as in Synthesis example 1, except that the compositions of the monomer components were changed as shown in Table 1.
[ Table 1]
BA: acrylic acid n-butyl ester
MEA: 2-Methoxyethyl acrylate
HEA: 2-Hydroxyethyl acrylate
AA: acrylic acid
AA-6: methyl methacrylate macromonomer (made by east Asia synthetic corporation of Chinese imperial China)
[ example 1]
To the polymer solution, E405 to 70B as an isocyanate-based crosslinking agent was added in an amount such that the solid content became 0.9 parts relative to 100 parts of the solid content of the (meth) acrylic copolymer (a-1): an adhesive composition was obtained by using a hexamethylene diisocyanate/butylene oxide-and epsilon-caprolactone-modified trimethylolpropane adduct (manufactured by Asahi Kasei corporation, 70% by mass as a solid content).
The obtained adhesive composition was coated on a release-treated PET film (spacer) so that the thickness after drying became 50 μm, and dried at 90 ℃ for 3 minutes to remove the solvent, thereby forming a coating film having a thickness of 50 μm. A spacer of a PET film base material having a peeling force smaller than that of the above spacer is bonded to the surface of the coating film opposite to the surface in contact with the PET film. Next, the resulting film was aged at 23 ℃ and 65% RH for 7 days to obtain an adhesive sheet having an adhesive layer with a thickness of 50 μm.
[ evaluation of]
<Fraction of gel>
The gel fraction was determined as follows. About 0.1g of the adhesive was collected from the adhesive layer of the above adhesive sheet and put into a sample bottle, and after adding 30mL of ethyl acetate and shaking for 4 hours, the content of the sample bottle was filtered through a 200-mesh stainless steel wire net, and the residue on the wire net was dried at 100 ℃ for 2 hours to measure the dried mass. The gel fraction of the adhesive layer was determined by the following formula.
Gel fraction (% by mass) (dry mass/adhesive harvest mass) × 100 (%)
<Resistance to blistering test>
Peeling off the adhesive sheetA spacer with small separation force, the exposed adhesive layer was adhered to a PET film (first layer) with a thickness of 100 μm, cut to a size of 60mm × 50mm, and then another spacer subjected to a peeling treatment was peeled off, and the exposed adhesive layer was adhered to a polycarbonate sheet PC1600 (thickness 2.0mm, weight ratio: 1.0021, density: 1.093-1.098 g/cm)3: taxilong Seika corporation (タキロンシーアイ) (second layer), and then held in an autoclave adjusted to 50 ℃ and 5 atm for 20 minutes to prepare a test plate. After the test plate was left to stand at 85 ℃/85% RH for 72 hours, the blister resistance was evaluated according to the criteria described in table 2.
Further, the weight ratio and density of the polycarbonate sheet were measured as follows.
[ Water-absorbing Capacity (weight ratio)]
The polycarbonate plate was left to stand at 85 ℃ for 72 hours in a dry atmosphere, and the weight (weight 1) thereof was measured immediately after the plate was taken out from the atmosphere. Thereafter, the polycarbonate plate was left to stand at 85 ℃ and 85% RH for 72 hours, and the weight (weight 2) thereof was measured immediately after the plate was taken out from the above-mentioned environment. The weight ratio (weight 2/weight 1) was calculated from the weights 1 and 2 before and after the introduction of the 85 ℃/85% RH atmosphere.
[ Density of]
Calculated from the relationship between the volume and the weight of the polycarbonate plate.
[ Table 2]
TABLE 2
<Whitening resistance test>
The separator having a low peeling force was peeled from the pressure-sensitive adhesive sheet, the exposed pressure-sensitive adhesive layer was adhered to a PET film (first layer) having a thickness of 100 μm, the resultant was cut into a size of 60 mm. times.50 mm, and then another separator having been peeled off was adhered to a polycarbonate plate (PC 1600; manufactured by Taxilong Seisaku Co., Ltd.) (second layer), followed by holding the plate in an autoclave adjusted to 50 ℃ and 5 atmospheres for 20 minutes to prepare a test plate. After the test plate was left at 85 ℃/85% RH for 72 hours, the presence or absence of whitening was visually confirmed according to the following criteria.
◎ No whitening appearance defects were observed at all.
○ the whitened appearance was slightly observed to be poor but was within a range where no problem was found in use.
X: a whitened appearance was observed in a wide range.
Examples 2 to 9, comparative examples 1 to 4, and reference examples 1 and 2]
An adhesive composition was prepared in the same manner as in example 1, except that the formulation composition of the adhesive composition was changed as described in table 3, and an adhesive sheet was obtained. The amount of the crosslinking agent is an amount relative to 100 parts of the (meth) acrylic copolymer.
In reference examples 1 and 2, NF2000VU (thickness 1.5mm, weight ratio 1.0006, density 1.124 to 1.132 g/cm) was used as a polycarbonate sheet3: mitsubishi gas chemical corporation (Mitsubishi ガス chemical).
[ Table 3]
E405-70B: hexamethylene diisocyanate/butylene oxide and epsilon-caprolactone-modified trimethylolpropane adduct (manufactured by Asahi Kasei corporation, solid content: 70% by mass)
MFA-75B: isocyanurate/epsilon-caprolactone-modified trimethylolpropane adduct of hexamethylene diisocyanate (manufactured by Asahi chemical Co., Ltd., solid content: 70% by mass)
E402-80B: hexamethylene diisocyanate/epsilon-caprolactone-modified trimethylolpropane adduct (manufactured by Asahi Kasei corporation, solid content 90% by mass)
D-90: biuret product of hexamethylene diisocyanate
(produced by Suzuo Kaisha (to Cao Kaisha, 90% by mass as solid content))
L-45: a reaction product of tolylene diisocyanate and trimethylolpropane (manufactured by Soken chemical Co., Ltd., solid content 45% by mass)
TD-75: reaction product of xylylene diisocyanate and trimethylolpropane (75% by mass as a solid content, available from Soken chemical Co., Ltd.)
In reference examples 1 and 2, the PC board having the above weight ratio of 1.0006 was used, and the blister resistance and the whitening resistance were good. However, in comparative example 1 in which an adhesive layer was formed in the same composition as in reference example 2 and a PC board having the above weight ratio of 1.0021 was used, the blister resistance was poor. Thus, the problem of durability is not remarkable when a PC board having low water absorption capacity is used, but the problem of durability occurs when a PC board having high water absorption capacity is used. This is a new problem, which has not been studied in the prior art.
On the other hand, in the examples, even in the case of using the PC board of the above-described weight ratio 1.0021, the blister resistance and the whitening resistance were good. Accordingly, the present invention can provide a laminate excellent in durability when a PC board having high water absorption capacity is used.
Description of the symbols
10-1 … resistive film type touch screen unit,
10-2 … electrostatic capacity type touch panel unit,
11-1 … upper laminate, 13-1 … lower laminate,
15-1 … upper laminate, 15-2 … lower laminate,
21-1 … surface supporting body, 21-2 … deep surface supporting body,
23-1, 23-2 … adhesive layer,
25-1 … upper electrode support, 25-2 … lower electrode support,
27-1 … transparent conductive film, 27-2 … transparent conductive film,
30 …, 32 … spacers, 34 … gaps,
51-1, 51-2 … surface support,
53-1, 53-2 … adhesive layer,
57-1, 57-2 … transparent conductive film,
60 … center support.
Claims (3)
1. A laminate comprising a first layer and a second layer laminated via an adhesive layer, characterized in that,
the second layer is a polycarbonate sheet having a weight ratio (weight after placement/weight before placement) of 1.0010 to 1.0050 before and after 72 hours of placement in an environment of 85 ℃/85% RH,
the pressure-sensitive adhesive layer is formed from a pressure-sensitive adhesive composition containing a (meth) acrylic copolymer (A) and an isocyanate-based crosslinking agent (B), wherein the (meth) acrylic copolymer (A) is a copolymer of monomer components including a polymerizable macromonomer and a crosslinkable functional group-containing monomer, and the isocyanate-based crosslinking agent (B) has an alkyleneoxy group having 2 or more carbon atoms.
2. The laminate according to claim 1, wherein the (meth) acrylic copolymer (A) is a copolymer of monomer components comprising 1 to 35 mass% of the polymerizable macromonomer and 0.5 to 20 mass% of the crosslinkable functional group-containing monomer.
3. A touch panel comprising the laminate of claim 1 or 2.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2017155249 | 2017-08-10 | ||
| JP2017-155249 | 2017-08-10 | ||
| PCT/JP2018/023118 WO2019031064A1 (en) | 2017-08-10 | 2018-06-18 | Laminated body and touch panel |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN110997320A true CN110997320A (en) | 2020-04-10 |
Family
ID=65272161
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201880051251.9A Pending CN110997320A (en) | 2017-08-10 | 2018-06-18 | Laminate and touch panel |
Country Status (5)
| Country | Link |
|---|---|
| JP (1) | JP7029456B2 (en) |
| KR (1) | KR102603519B1 (en) |
| CN (1) | CN110997320A (en) |
| TW (1) | TWI823857B (en) |
| WO (1) | WO2019031064A1 (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP7338318B2 (en) * | 2019-08-21 | 2023-09-05 | 王子ホールディングス株式会社 | Adhesive sheet, adhesive sheet with release sheet and laminate |
| WO2021033704A1 (en) * | 2019-08-21 | 2021-02-25 | 王子ホールディングス株式会社 | Adhesive sheet, adhesive sheet with release sheet, laminate, and method for producing laminate |
| JP7338319B2 (en) * | 2019-08-21 | 2023-09-05 | 王子ホールディングス株式会社 | Laminate manufacturing method |
| WO2021044928A1 (en) * | 2019-09-05 | 2021-03-11 | Ａｇｃ株式会社 | Conductor-equipped laminate, and antenna unit |
| KR20220062091A (en) * | 2019-10-28 | 2022-05-13 | 소켄 케미칼 앤드 엔지니어링 캄파니, 리미티드 | Pressure-sensitive adhesive composition, pressure-sensitive adhesive sheet and optical member |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102876263A (en) * | 2011-07-12 | 2013-01-16 | 综研化学株式会社 | Adhesive, adhesive sheet and laminate for touch panel |
| CN105018006A (en) * | 2014-04-24 | 2015-11-04 | 综研化学株式会社 | Adhesive composition, adhesive layer, adhesive sheet and laminate for touch panel |
| CN105385371A (en) * | 2014-09-01 | 2016-03-09 | 日东电工株式会社 | Carrier film for transparent conductive film and laminated body |
| CN106164718A (en) * | 2014-03-18 | 2016-11-23 | 综研化学株式会社 | Polaroid adhesive composition, adhesive phase, bonding sheet and the polaroid of band adhesive phase |
| CN106795407A (en) * | 2014-10-14 | 2017-05-31 | 综研化学株式会社 | Polarizer adhesive composition, bonding sheet, polarizer and layered product with adhesive phase |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS58217347A (en) * | 1982-06-11 | 1983-12-17 | 日本板硝子株式会社 | Laminated panel and its manufacture |
| JP5757809B2 (en) * | 2011-07-13 | 2015-08-05 | 綜研化学株式会社 | Laminated body and touch panel having the laminated body |
| KR101570559B1 (en) * | 2012-12-24 | 2015-11-19 | 제일모직주식회사 | Protective sheet for liquid crystal display and liquid crystal display comprising the same |
| EP3077432B1 (en) | 2013-12-04 | 2019-04-10 | 3M Innovative Properties Company | Optically clear adhesives for durable plastic bonding |
| JP6334721B2 (en) | 2014-10-01 | 2018-05-30 | 綜研化学株式会社 | Touch panel pressure-sensitive adhesive composition, pressure-sensitive adhesive sheet, and laminate |
| JP6632350B2 (en) * | 2015-11-27 | 2020-01-22 | 三星エスディアイ株式会社ＳＡＭＳＵＮＧ ＳＤＩ Ｃｏ．， ＬＴＤ． | Pressure-sensitive adhesive for optical film, pressure-sensitive adhesive layer, optical member, and image display device |
-
2018
- 2018-06-18 CN CN201880051251.9A patent/CN110997320A/en active Pending
- 2018-06-18 JP JP2019535007A patent/JP7029456B2/en active Active
- 2018-06-18 KR KR1020207004007A patent/KR102603519B1/en active IP Right Grant
- 2018-06-18 WO PCT/JP2018/023118 patent/WO2019031064A1/en active Application Filing
- 2018-07-12 TW TW107124100A patent/TWI823857B/en active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102876263A (en) * | 2011-07-12 | 2013-01-16 | 综研化学株式会社 | Adhesive, adhesive sheet and laminate for touch panel |
| CN106164718A (en) * | 2014-03-18 | 2016-11-23 | 综研化学株式会社 | Polaroid adhesive composition, adhesive phase, bonding sheet and the polaroid of band adhesive phase |
| CN105018006A (en) * | 2014-04-24 | 2015-11-04 | 综研化学株式会社 | Adhesive composition, adhesive layer, adhesive sheet and laminate for touch panel |
| CN105385371A (en) * | 2014-09-01 | 2016-03-09 | 日东电工株式会社 | Carrier film for transparent conductive film and laminated body |
| CN106795407A (en) * | 2014-10-14 | 2017-05-31 | 综研化学株式会社 | Polarizer adhesive composition, bonding sheet, polarizer and layered product with adhesive phase |
Also Published As
| Publication number | Publication date |
|---|---|
| JP7029456B2 (en) | 2022-03-03 |
| TWI823857B (en) | 2023-12-01 |
| WO2019031064A1 (en) | 2019-02-14 |
| KR20200040239A (en) | 2020-04-17 |
| JPWO2019031064A1 (en) | 2020-08-27 |
| KR102603519B1 (en) | 2023-11-17 |
| TW201910117A (en) | 2019-03-16 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| TWI704200B (en) | Adhesive sheet | |
| CN110997320A (en) | Laminate and touch panel | |
| JP5797025B2 (en) | Capacitive touch panel | |
| TWI666282B (en) | Adhesive composition, adhesion layer, adhesion sheet and laminated product for touch panel | |
| TWI445791B (en) | Pressure-sensitive adhesive film for touch panel and touch panel | |
| CN109021889B (en) | Image display device | |
| TW201410817A (en) | Pressure-sensitive adhesive, pressure-sensitive adhesive layer, and pressure-sensitive adhesive sheet | |
| JP6921571B2 (en) | Adhesive composition and adhesive sheet | |
| WO2014156200A1 (en) | Adhesive agent and adhesive sheet produced using same | |
| JP6013092B2 (en) | Double-sided adhesive sheet | |
| KR20170119641A (en) | Pressure sensitive adhesive, optical pressure sensitive adhesive sheet, pressure sensitive adhesive sheet for polarizing plate, and liquid crystal cell member | |
| KR20220062091A (en) | Pressure-sensitive adhesive composition, pressure-sensitive adhesive sheet and optical member | |
| CN106916555B (en) | Adhesive, adhesive sheet using same, polarizing plate adhesive sheet, and liquid crystal cell member | |
| KR101584841B1 (en) | Conductive laminate | |
| US20140065403A1 (en) | Double-sided pressure-sensitive adhesive sheet | |
| JP2015040215A (en) | Tacky adhesive composition for touch panel, and tacky-adhesive tape for touch panel | |
| TWI840331B (en) | Adhesive composition and adhesive sheet | |
| JP6839495B2 (en) | Adhesive composition and adhesive sheet | |
| TW201446914A (en) | Adhesive composition and optical adhesive tape |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |