CN110776857B - Adhesive composition, adhesive and adhesive sheet - Google Patents

Adhesive composition, adhesive and adhesive sheet Download PDF

Info

Publication number
CN110776857B
CN110776857B CN201910701370.0A CN201910701370A CN110776857B CN 110776857 B CN110776857 B CN 110776857B CN 201910701370 A CN201910701370 A CN 201910701370A CN 110776857 B CN110776857 B CN 110776857B
Authority
CN
China
Prior art keywords
adhesive
meth
acrylate
mass
acrylate polymer
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.)
Active
Application number
CN201910701370.0A
Other languages
Chinese (zh)
Other versions
CN110776857A (en
Inventor
小泽祐树
荒井隆行
小鲭翔
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Lintec Corp
Original Assignee
Lintec Corp
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Lintec Corp filed Critical Lintec Corp
Publication of CN110776857A publication Critical patent/CN110776857A/en
Application granted granted Critical
Publication of CN110776857B publication Critical patent/CN110776857B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • 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
    • C09J133/14—Homopolymers or copolymers of esters of esters containing halogen, nitrogen, sulfur or oxygen atoms in addition to the carboxy oxygen
    • 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
    • C09J133/08—Homopolymers or copolymers of acrylic acid esters
    • 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
    • C09J133/10—Homopolymers or copolymers of methacrylic acid esters
    • 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
    • C09J7/00—Adhesives in the form of films or foils
    • C09J7/10—Adhesives in the form of films or foils without carriers
    • 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
    • C09J7/00—Adhesives in the form of films or foils
    • C09J7/30—Adhesives in the form of films or foils characterised by the adhesive composition
    • 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
    • C09J7/00—Adhesives in the form of films or foils
    • C09J7/40—Adhesives in the form of films or foils characterised by release liners
    • 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
    • C09J2203/00—Applications of adhesives in processes or use of adhesives in the form of films or foils
    • C09J2203/318—Applications of adhesives in processes or use of adhesives in the form of films or foils for the production of liquid crystal displays
    • 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
    • C09J2203/00—Applications of adhesives in processes or use of adhesives in the form of films or foils
    • C09J2203/326—Applications of adhesives in processes or use of adhesives in the form of films or foils for bonding electronic components such as wafers, chips or semiconductors
    • 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
    • C09J2301/00—Additional features of adhesives in the form of films or foils
    • C09J2301/30—Additional features of adhesives in the form of films or foils characterized by the chemical, physicochemical or physical properties of the adhesive or the carrier
    • C09J2301/312—Additional features of adhesives in the form of films or foils characterized by the chemical, physicochemical or physical properties of the adhesive or the carrier parameters being the characterizing feature

Landscapes

  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Adhesives Or Adhesive Processes (AREA)
  • Adhesive Tapes (AREA)

Abstract

The invention provides an adhesive composition, an adhesive and an adhesive sheet, which can reduce haze value under normal temperature environment and low temperature environment under the condition of containing (methyl) acrylate polymer and polyrotaxane compound. The adhesive composition contains a (meth) acrylate polymer (A) and a polyrotaxane compound (B), wherein the (meth) acrylate polymer (A) contains an aromatic ring-containing monomer and a reactive functional group-containing monomer as monomer units constituting the polymer, the content of the aromatic ring-containing monomer as a structural monomer unit in the (meth) acrylate polymer (A) is 2.5 mass% or more and 30 mass% or less, and the content of the reactive functional group-containing monomer as a structural monomer unit in the (meth) acrylate polymer (A) is 5 mass% or more and 30 mass% or less.

Description

Adhesive composition, adhesive and adhesive sheet
Technical Field
The present invention relates to an adhesive composition, an adhesive and an adhesive sheet, and particularly to an adhesive composition, an adhesive and an adhesive sheet suitable for use in optical applications at low temperatures.
Background
Various mobile electronic devices in recent years, such as mobile phones, smartphones, and tablet terminals, include a display (monitor) using a display module including a liquid crystal element, a light emitting diode (LED element), an organic electroluminescence (organic EL) element, and the like.
In the display, a protective panel is generally provided on the surface side of the display body module. A gap is provided between the protective panel and the display body module so that the deformed protective panel does not collide with the display body module even when the protective panel is deformed by an external force.
However, if the above-described gap exists, that is, if the air layer exists, the reflection loss of light due to the difference in refractive index between the protection panel and the air layer and the difference in refractive index between the air layer and the display body module is large, which causes a problem that the image quality of the display device is degraded.
Therefore, it has been proposed to improve the image quality of a display by filling a gap between a protective panel and a display module with an adhesive layer. However, the frame-shaped printed layer may exist as a step on the display module side of the protective panel. If the adhesive layer does not follow the step, the adhesive layer floats up near the step, and reflection loss of light occurs. Therefore, the adhesive agent layer is required to have step following properties.
In view of the above, patent document 1 proposes an optical transparent adhesive sheet having an adhesive layer containing: a (meth) acrylate polymer containing a hydroxyl group-containing monomer as a structural monomer and a polyrotaxane. The present invention uses polyrotaxane as described above to slide the crosslinking point of the (meth) acrylate polymer, thereby achieving a step following property based on both crosslinking and flexibility.
Documents of the prior art
Patent document
Patent document 1: japanese patent laid-open publication No. 2017-179230
Disclosure of Invention
Technical problems to be solved by the invention
However, when the adhesive layer is left in a low-temperature environment, the compatibility between the (meth) acrylate polymer and the polyrotaxane decreases, and the haze value of the adhesive layer increases. In this case, transparency for optical use cannot be secured.
The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an adhesive composition, an adhesive and an adhesive sheet which can reduce a haze value in a normal temperature environment and a low temperature environment when containing a (meth) acrylate polymer and a polyrotaxane compound.
Means for solving the problems
In order to achieve the above object, the present invention provides an adhesive composition comprising a (meth) acrylate polymer (a) and a polyrotaxane compound (B), wherein the (meth) acrylate polymer (a) contains an aromatic ring-containing monomer and a reactive functional group-containing monomer as monomer units constituting the polymer, the aromatic ring-containing monomer as a structural monomer unit in the (meth) acrylate polymer (a) is contained in an amount of 2.5 mass% or more and 30 mass% or less, and the reactive functional group-containing monomer as a structural monomer unit in the (meth) acrylate polymer (a) is contained in an amount of 5 mass% or more and 30 mass% or less (invention 1).
In the adhesive layer obtained from the adhesive composition of the invention (invention 1), the haze value in the normal temperature environment and the low temperature environment can be reduced by containing the monomer as a monomer unit constituting the polymer in the amount described above in the (meth) acrylate polymer (a). In addition, in the adhesive agent layer, by containing the polyrotaxane compound (B), the stress relaxation property is improved, and the step following property is excellent.
In the above invention (invention 1), it is preferable that: the content of the polyrotaxane compound (B) in the adhesive composition is 1 part by mass or more and 20 parts by mass or less with respect to 100 parts by mass of the (meth) acrylate polymer (a) (invention 2).
In the above inventions (inventions 1 and 2), the crosslinking agent (C) (invention 3) is preferably contained.
The second aspect of the present invention provides an adhesive obtained by crosslinking the adhesive compositions (invention 1 to 3) (invention 4).
The third aspect of the present invention provides an adhesive sheet comprising two release sheets and an adhesive layer sandwiched between the release sheets so as to be in contact with release surfaces of the two release sheets, wherein the adhesive layer is composed of the adhesive (invention 4) (invention 5).
In the above invention (invention 5), the pressure-sensitive adhesive sheet is preferably an optical pressure-sensitive adhesive sheet (invention 6).
In the above invention (invention 6), the pressure-sensitive adhesive sheet is preferably an optical pressure-sensitive adhesive sheet which is supposed to be used in an environment of-40 ℃ (invention 7).
A fourth aspect of the present invention provides an adhesive sheet comprising an adhesive layer, wherein the adhesive layer has a haze value of 8% or less at 23 ℃, and the adhesive layer has a haze value of 8% or less after the adhesive sheet is stored at-40 ℃ for 3 days (invention 8).
A fifth aspect of the present invention provides a structure (including a display) comprising one display constituent member, another display constituent member, and an adhesive layer for bonding the one display constituent member and the another display constituent member to each other, wherein the adhesive layer uses the adhesive layer of the pressure-sensitive adhesive sheet (invention 8).
One or both of the one display element constituting member and the other display element constituting member may have a step on the adhesive agent layer side or may not have a step on the adhesive agent layer side. Further, one or both of the one display body constituting member and the other display body constituting member may be a hard plate. Further, the one display body constituting member and the other display body constituting member may be both hard plates, and one or both of the hard plates may or may not have a level difference on the adhesive agent layer side.
Effects of the invention
When the adhesive composition, the adhesive and the adhesive sheet of the present invention contain a (meth) acrylate polymer and a polyrotaxane compound, the haze value can be reduced in a normal temperature environment and a low temperature environment.
Drawings
Fig. 1 is a sectional view of an adhesive sheet according to an embodiment of the present invention.
Fig. 2 is a cross-sectional view of a display body according to an embodiment of the present invention.
Description of the reference numerals
1: an adhesive sheet; 11: an adhesive layer; 12a, 12b: a release sheet; 2: a display body; 21: a first display body constituting member; 22: a second display body constituting member; 3: and printing the layer.
Detailed Description
Hereinafter, embodiments of the present invention will be described.
[ adhesive composition ]
The adhesive composition of the present embodiment (hereinafter, may be referred to as "adhesive composition P") contains a (meth) acrylate polymer (a) and a polyrotaxane compound (B), and preferably further contains a crosslinking agent (C). The (meth) acrylate polymer (A) contains an aromatic ring-containing monomer and a reactive functional group-containing monomer as monomer units constituting the polymer. The content of the aromatic ring-containing monomer as a structural monomer unit in the (meth) acrylate polymer (a) is 2.5 to 30 mass%, and the content of the reactive functional group-containing monomer as a structural monomer unit in the (meth) acrylate polymer (a) is 5 to 25 mass%. In the present specification, (meth) acrylic acid means acrylic acid and methacrylic acid. Other similar terms are also the same. Further, the term "polymer" is intended to include the concept of "copolymer".
The adhesive obtained from the adhesive composition P can reduce the haze value in an ambient temperature environment by containing the monomer as a monomer unit constituting the (meth) acrylate polymer (a) in the above-mentioned amount. Further, even when the composition is left in a low-temperature environment, the compatibility between the (meth) acrylate polymer (a) and the polyrotaxane compound (B) can be maintained, and the increase in the haze value can be suppressed. For example, the haze value of an adhesive sheet having an adhesive layer of 50 μm thickness composed of the adhesive can be suppressed to 8% or less after storage for 3 days at-40 ℃.
The polyrotaxane compound (B) has a mechanical bond between the cyclic molecule and the linear molecule passing through the cyclic molecule, and the cyclic molecule can freely move (slide) on the linear molecule. When the polyrotaxane compound (B) is contained in the adhesive obtained from the adhesive composition P, the stress relaxation property is improved, and the step following property is excellent.
In particular, when the adhesive composition P contains the crosslinking agent (C), when the adhesive composition P is crosslinked, the reactive group of the crosslinking agent (C) reacts with the reactive group of the cyclic molecule of the polyrotaxane compound (B) to form a crosslinking agent adduct. The (meth) acrylate polymer (a) is bonded to 1 cyclic molecule of the polyrotaxane compound (B) through the crosslinking agent (C) in the crosslinking agent adduct by a reactive functional group derived from a reactive functional group-containing monomer contained in the polymer, and similarly, it is presumed that the other (meth) acrylate polymer (a) is bonded to the other cyclic molecule of the polyrotaxane compound (B). As a result, a structure (crosslinked structure) in which the plurality of (meth) acrylate polymers (a) are crosslinked with each other via the polyrotaxane compound (B) having the slidable mechanical bond is formed. By containing the crosslinked structure, the obtained adhesive is more excellent in stress relaxation property and is more excellent in step following property. Specifically, when the adhesive layer composed of the adhesive is attached to a member having a step (for example, a display element-constituting member), the adhesive layer is likely to follow the step, and generation of a gap, floating, or the like in the vicinity of the step can be suppressed. Further, even when the resulting mixture is left to stand under high-temperature and high-humidity conditions, for example, 85 ℃ RH% for 72 hours, the occurrence of bubbles, floating, peeling, and the like in the vicinity of the step can be suppressed.
Further, it is not necessary that all the adhesives obtained have the above-described structure, and 2 (meth) acrylate polymers (a) may be directly bonded to each other with a crosslinking agent (C) without the polyrotaxane compound (B).
(1) Each component
(1-1) (meth) acrylate ester Polymer (A)
The (meth) acrylate polymer (a) in the present embodiment contains an aromatic ring-containing monomer and a reactive functional group-containing monomer as monomer units constituting the polymer.
As the aromatic ring-containing monomer, (meth) acrylate having an aromatic ring is preferable from the viewpoint of polymerizability. Examples of the aromatic ring include benzene ring, naphthalene ring, anthracene ring, biphenyl ring, fluorene ring, and the like, and among them, benzene ring is preferable from the viewpoint of reducing the haze value in a low-temperature environment.
Examples of the aromatic ring-containing monomer include phenyl (meth) acrylate, 2-phenylethyl (meth) acrylate, benzyl (meth) acrylate, naphthyl (meth) acrylate, 2-phenoxyethyl (meth) acrylate, phenoxybutyl (meth) acrylate, ethoxylated o-phenylphenol acrylate, and phenoxydiethylene glycol (meth) acrylate. Among these, 2-phenoxyethyl (meth) acrylate, benzyl (meth) acrylate, or 2-phenylethyl (meth) acrylate is preferable from the viewpoint of reducing the haze value in a low-temperature environment, and 2-phenoxyethyl acrylate, benzyl acrylate, or 2-phenylethyl acrylate is particularly preferable, and 2-phenoxyethyl acrylate is more preferable. These may be used alone or in combination of two or more.
The (meth) acrylate polymer (a) contains 2.5% by mass or more of an aromatic ring-containing monomer, preferably 3.0% by mass or more of an aromatic ring-containing monomer, and particularly preferably 5.0% by mass or more of an aromatic ring-containing monomer as a monomer unit constituting the polymer. This can suppress an increase in the haze value of the obtained adhesive in a low-temperature environment. Further, from the viewpoint of further improving the step difference followability, the aromatic ring-containing monomer is contained at 30% by mass or less, preferably at 25% by mass or less, particularly preferably at 20% by mass or less, and further preferably at 12% by mass or less. This can suppress the haze value of the obtained adhesive in a normal temperature environment to be low.
The reactive functional group-containing monomer contained as a monomer unit constituting the (meth) acrylate polymer (a) is preferably a monomer containing a hydroxyl group in the molecule (hydroxyl group-containing monomer), a monomer containing a carboxyl group in the molecule (carboxyl group-containing monomer), a monomer containing an amino group in the molecule (amino group-containing monomer), or the like. These reactive functional group-containing monomers may be used alone or in combination of two or more.
Among the above-mentioned reactive functional group-containing monomers, a hydroxyl group-containing monomer or a carboxyl group-containing monomer is preferable from the viewpoint of suppressing the haze value at low temperature and room temperature. The (meth) acrylate polymer (a) in the present embodiment may contain both a hydroxyl group-containing monomer and a carboxyl group-containing monomer as monomer units constituting the polymer, and preferably contains the hydroxyl group-containing monomer and the carboxyl group-containing monomer individually, and particularly preferably contains only the hydroxyl group-containing monomer.
Examples of the hydroxyl group-containing monomer include hydroxyalkyl (meth) acrylates such as 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 3-hydroxybutyl (meth) acrylate, and 4-hydroxybutyl (meth) acrylate. When the (meth) acrylic acid ester polymer (A) contains a hydroxyl group-containing monomer as a monomer unit constituting the polymer, from the viewpoint of reducing the haze value in a low-temperature environment and the reactivity with the crosslinking agent (C), among the above, 2-hydroxyethyl (meth) acrylate or 4-hydroxybutyl (meth) acrylate is preferable, 2-hydroxyethyl acrylate or 4-hydroxybutyl acrylate is particularly preferable, and 2-hydroxyethyl acrylate is more preferable. These may be used alone or in combination of two or more.
Examples of the carboxyl group-containing monomer include ethylenically unsaturated carboxylic acids such as acrylic acid, methacrylic acid, crotonic acid, maleic acid, itaconic acid, and citraconic acid. When the (meth) acrylate polymer (a) contains a carboxyl group-containing monomer as a monomer unit constituting the polymer, acrylic acid is preferable among the above from the viewpoint of reducing the haze value in a low-temperature environment and the viewpoint of reactivity with the crosslinking agent (C). These may be used alone or in combination of two or more.
The content of the reactive functional group-containing monomer as a structural monomer unit in the (meth) acrylate polymer (a) (the total amount of the reactive functional group-containing monomers when 2 or more species are contained) is 5% by mass or more, preferably 10% by mass or more, and particularly preferably 15% by mass or more. The content is 30% by mass or less, preferably 25% by mass or less, and particularly preferably 20% by mass or less. When the content of the reactive functional group-containing monomer is within the above range, the increase in haze value of the obtained adhesive in a low-temperature environment can be suppressed, and the obtained adhesive can be excellent in step following property.
When the (meth) acrylate polymer (a) contains only a hydroxyl group-containing monomer as a reactive functional group-containing monomer which is a monomer unit constituting the polymer, the content thereof is preferably 7% by mass or more, particularly preferably 13% by mass or more, and further preferably 15% by mass or more. The content is preferably 30% by mass or less, particularly preferably 25% by mass or less, and further preferably 20% by mass or less.
When the (meth) acrylate polymer (a) contains only a carboxyl group-containing monomer as a reactive functional group-containing monomer that is a monomer unit constituting the polymer, the content thereof is preferably 5% by mass or more, particularly preferably 7% by mass or more, and more preferably 9% by mass or more. The content is preferably 25% by mass or less, particularly preferably 20% by mass or less, and further preferably 15% by mass or less.
The (meth) acrylate polymer (a) preferably contains an alkyl (meth) acrylate as a monomer unit constituting the polymer. This can exhibit good adhesion. The alkyl group may be linear or branched.
From the viewpoint of adhesiveness, the alkyl (meth) acrylate is preferably an alkyl (meth) acrylate in which the alkyl group has 1 to 20 carbon atoms. Examples of the alkyl (meth) acrylate in which the alkyl group has 1 to 20 carbon atoms include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n-butyl (meth) acrylate, n-pentyl (meth) acrylate, n-hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isooctyl (meth) acrylate, n-decyl (meth) acrylate, n-dodecyl (meth) acrylate, tetradecyl (meth) acrylate, hexadecyl (meth) acrylate, and octadecyl (meth) acrylate.
Among them, from the viewpoint of effectively imparting adhesive force and ensuring good step following property, an alkyl (meth) acrylate in which the alkyl group has 2 to 12 carbon atoms is more preferable, an alkyl acrylate in which the alkyl group has 4 to 10 carbon atoms is particularly preferable, and an alkyl acrylate in which the alkyl group has 5 to 8 carbon atoms is further preferable. Specifically, n-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, or isooctyl (meth) acrylate is preferable, n-butyl acrylate, 2-ethylhexyl acrylate, or isooctyl acrylate is particularly preferable, and 2-ethylhexyl acrylate or isooctyl acrylate is further preferable. These may be used alone or in combination of two or more.
From the viewpoint of imparting tackiness, the (meth) acrylate polymer (a) preferably contains, as a monomer unit constituting the polymer, an alkyl (meth) acrylate having 1 to 20 carbon atoms, which contains an alkyl group in an amount of 50 mass%, more preferably 60 mass% or more, and particularly preferably 70 mass%. From the viewpoint of ensuring the blending amount of other components, the alkyl (meth) acrylate having 1 to 20 carbon atoms containing an alkyl group is preferably contained by 95% by mass or less, more preferably 90% by mass or less, and particularly preferably 85% by mass or less.
The (meth) acrylate polymer (a) may contain other monomers as a monomer unit constituting the polymer, as required. In order not to inhibit the action of the reactive functional group-containing monomer, it is also preferable that the other monomer does not contain a reactive functional group. Examples of the monomer having no reactive functional group include alicyclic structure-containing monomers such as adamantyl (meth) acrylate and isobornyl (meth) acrylate, alkoxyalkyl (meth) acrylates such as methoxyethyl (meth) acrylate and ethoxyethyl (meth) acrylate, and vinyl acetate. These may be used alone or in combination of two or more.
The polymerization form of the (meth) acrylate polymer (a) may be a random copolymer or a block copolymer.
The lower limit of the weight average molecular weight of the (meth) acrylate polymer (a) is preferably 20 ten thousand or more, particularly preferably 30 ten thousand or more, and more preferably 40 ten thousand or more. When the lower limit of the weight average molecular weight is as described above, the cohesive force of the obtained adhesive can be ensured, and the step following property under high-temperature and high-humidity conditions can be further improved. The upper limit of the weight average molecular weight is preferably 180 ten thousand or less, more preferably 150 ten thousand or less, particularly preferably 120 ten thousand or less, and further preferably 75 ten thousand or less. When the upper limit of the weight average molecular weight is as described above, the flexibility of the obtained adhesive can be ensured, and the step following property can be further improved. Here, the weight average molecular weight in the present specification is a value in terms of standard polystyrene measured by a Gel Permeation Chromatography (GPC) method.
In the adhesive composition P, one kind of the (meth) acrylate polymer (a) may be used alone, or two or more kinds may be used in combination.
The lower limit of the content of the (meth) acrylate polymer (a) in the adhesive composition P of the present embodiment is preferably 60% by mass or more, particularly preferably 70% by mass or more, and more preferably 80% by mass or more. When the lower limit of the content of the (meth) acrylate polymer (a) is set to the above range, the adhesive strength of the obtained adhesive is good. The upper limit of the content of the (meth) acrylate polymer (a) is preferably 98% by mass or less, particularly preferably 97% by mass or less, and more preferably 95% by mass or less. When the upper limit of the content of the (meth) acrylate polymer (a) is set to the above range, the content of the polyrotaxane compound (B) (and the crosslinking agent (C)) can be secured, and the step following property of the obtained adhesive can be improved.
(1-2) polyrotaxane Compound (B)
The polyrotaxane compound (B) is a compound in which a straight-chain molecule passes through at least the opening of 2 cyclic molecules and has blocking groups at both ends of the straight-chain molecule. In the polyrotaxane compound (B), the cyclic molecule can freely move on the linear molecule, but the cyclic molecule cannot escape from the linear molecule due to the end capping group. That is, the linear molecules and the cyclic molecules are not chemically bonded by covalent bonds or the like, but are maintained in their forms by so-called mechanical bonds.
The polyrotaxane compound (B) of the present embodiment preferably has a cyclic molecule having a reactive group. The reactive group is not particularly limited as long as it can react with the reactive group of the crosslinking agent (C), and examples thereof include a hydroxyl group, a carboxyl group and the like, and among them, a hydroxyl group is preferable.
The polyrotaxane compound (B) according to the present embodiment preferably has a cyclic oligosaccharide as a cyclic molecule. The cyclic oligosaccharide has a hydroxyl group as a reactive group in an unmodified state. Further, by using a cyclic oligosaccharide as the cyclic molecule of the polyrotaxane compound (B), an effect by the movement of the cyclic molecule on the linear molecule can be easily exhibited by selecting an appropriate ring diameter. Further, various substituents and the like can be easily introduced, and thereby the physical properties of the obtained adhesive can be adjusted. Further, cyclic oligosaccharides have an advantage of being easily available. In the present specification, "cyclic" of "cyclic molecule" or "cyclic oligosaccharide" means substantially "cyclic". That is, if the molecule can move on a linear molecule, the cyclic molecule may not be completely closed, and may have a helical structure, for example.
The cyclic oligosaccharide preferably includes cyclodextrins such as α -cyclodextrin, β -cyclodextrin, and γ -cyclodextrin, and among these, α -cyclodextrin is particularly preferred. The cyclic molecule of the polyrotaxane compound (B) may be present in a mixture of 2 or more kinds in the polyrotaxane compound (B) or the adhesive composition P.
The hydroxyl group of the cyclic oligosaccharide as a reactive group may be a hydroxyl group originally contained in the cyclic oligosaccharide (referred to as a state before modification) or a hydroxyl group introduced as a substituent into the cyclic oligosaccharide.
The lower limit of the hydroxyl value of the cyclic molecule is preferably 10mgKOH/g or more, more preferably 30mgKOH/g or more, and particularly preferably 50mgKOH/g or more. When the lower limit of the hydroxyl value is as described above, the polyrotaxane compound (B) can sufficiently react with the crosslinking agent (C). The upper limit of the hydroxyl value of the cyclic molecule is preferably 1000mgKOH/g or less, more preferably 200mgKOH/g or less, and particularly preferably 100mgKOH/g or less. If the upper limit of the hydroxyl value exceeds the above-mentioned value, a plurality of crosslinks are formed in the same cyclic molecule, and the cyclic molecule itself becomes a crosslinking point, and the effect of the crosslinking point as the polyrotaxane compound (B) as a whole cannot be exerted, and as a result, sufficient flexibility may not be secured in the obtained adhesive.
The linear molecule of the polyrotaxane compound (B) is a molecule or a substance which is enclosed in a cyclic molecule and can be integrated not by a chemical bond such as a covalent bond but by a mechanical bond, and is not particularly limited as long as it is a linear molecule. In the present specification, the "linear chain" of the "linear molecule" basically means a "linear chain". That is, the linear molecule may have a branch as long as the cyclic molecule can move on the linear molecule.
The linear molecules of the polyrotaxane compound (B) are preferably polyethylene glycol, polypropylene glycol, polyisoprene, polyisobutylene, polybutadiene, polytetrahydrofuran, polyacrylate, polydimethylsiloxane, polyethylene, polypropylene, or the like, and these linear molecules may be present in a mixture of 2 or more in the adhesive composition P.
The lower limit of the number average molecular weight of the linear molecule of the polyrotaxane compound (B) is preferably 3,000 or more, particularly preferably 10,000 or more, and more preferably 20,000 or more. When the lower limit of the number average molecular weight is the above, the amount of movement of the cyclic molecule in the linear molecule can be secured, and flexibility due to the crosslinked structure of the polyrotaxane compound (B) can be sufficiently obtained. The upper limit of the number average molecular weight of the linear molecule of the polyrotaxane compound (B) is preferably 300,000 or less, particularly preferably 200,000 or less, and more preferably 100,000 or less. When the upper limit of the number average molecular weight is as described above, the solubility of the polyrotaxane compound (B) in the solvent is good.
The end-capping group of the polyrotaxane compound (B) is not particularly limited as long as it is a group capable of maintaining a form in which a cyclic molecule passes through a linear molecule and becomes a threading shape. Examples of such a group include bulky groups and ionic groups.
Specifically, the blocking group of the polyrotaxane compound (B) is preferably a main chain or a side chain of a polymer having a number average molecular weight of 1,000 to 1,000,000, such as a dinitrophenyl group, a cyclodextrin group, an adamantyl group, a trityl group, a fluorescein group, a pyrene group, an anthracene group, or the like, and these blocking groups may be present in 2 or more kinds in the polyrotaxane compound (B) or the adhesive composition P.
The polyrotaxane compound (B) described above can be obtained by a conventionally known method (for example, the method described in Japanese patent application laid-open No. 2005-154675).
The lower limit of the content of the polyrotaxane compound (B) in the adhesive composition P of the present embodiment is preferably 1 part by mass or more, particularly preferably 2 parts by mass or more, and more preferably 4 parts by mass or more, relative to 100 parts by mass of the (meth) acrylate polymer (a). When the lower limit of the content of the polyrotaxane compound (B) is as described above, the stress relaxation property of the obtained adhesive becomes higher, and thus the step following property is more excellent. The upper limit of the content of the polyrotaxane compound (B) is preferably 20 parts by mass or less, more preferably 15 parts by mass or less, particularly preferably 10 parts by mass or less, and further preferably 8 parts by mass or less. If the upper limit of the content of the polyrotaxane compound (B) is as described above, the haze value of the obtained adhesive in a normal temperature environment can be suppressed from becoming too high.
(1-3) crosslinking agent (C)
The crosslinking agent (C) has a reactive group. The reactive group may be any group that can react with the hydroxyl group or carboxyl group of the (meth) acrylate polymer (a) and the reactive group of the cyclic molecule of the polyrotaxane compound (B). The crosslinking agent (C) forms a crosslinking agent adduct with the polyrotaxane compound (B). And, the crosslinking agent adduct crosslinks the (meth) acrylate polymers (a) to each other.
Examples of the reactive group of the crosslinking agent (C) include an isocyanate group, an epoxy group, an amino group, a vinylsulfonyl group, and an organic metal. Examples of the crosslinking agent (C) having such a reactive group include isocyanate crosslinking agents, epoxy crosslinking agents, amine crosslinking agents, vinyl sulfone crosslinking agents, organic titanium-zirconium compounds, and the like. Among them, isocyanate crosslinking agents having high reactivity with hydroxyl groups are preferable. The isocyanate-based crosslinking agent can sufficiently perform addition of the crosslinking agent to the polyrotaxane compound (B) having a hydroxyl group as a reactive group, and thus the stress relaxation property of the obtained adhesive can be further improved. The crosslinking agent (C) may be used alone or in combination of two or more.
The isocyanate-based crosslinking agent contains at least a polyisocyanate compound. Examples of the polyisocyanate compound include aromatic polyisocyanates such as tolylene diisocyanate, diphenylmethane diisocyanate, and xylylene diisocyanate, aliphatic polyisocyanates such as hexamethylene diisocyanate, alicyclic polyisocyanates such as isophorone diisocyanate and hydrogenated diphenylmethane diisocyanate, biuret and isocyanurate products thereof, and adducts thereof with low-molecular active hydrogen-containing compounds such as ethylene glycol, propylene glycol, neopentyl glycol, trimethylolpropane, and castor oil. Among them, trimethylolpropane-modified aromatic polyisocyanates are preferable from the viewpoint of reactivity with hydroxyl groups, and trimethylolpropane-modified tolylene diisocyanate and trimethylolpropane-modified xylylene diisocyanate are particularly preferable.
When the (meth) acrylate polymer (a) contains a carboxyl group-containing monomer as a monomer unit constituting the polymer, an epoxy-based crosslinking agent having high reactivity with a carboxyl group is preferably used as the crosslinking agent (C).
Examples of the epoxy-based crosslinking agent include 1, 3-bis (N, N-diglycidylaminomethyl) cyclohexane, N, N, N ', N' -tetraglycidyl-m-xylylenediamine, ethylene glycol diglycidyl ether, 1, 6-hexanediol diglycidyl ether, trimethylolpropane diglycidyl ether, diglycidylaniline, and diglycidylamine. Among them, N' -tetraglycidyl-m-xylylenediamine is preferable from the viewpoint of reactivity with a carboxyl group.
The lower limit of the content of the crosslinking agent (C) in the adhesive composition P is preferably 0.01 parts by mass or more, particularly preferably 0.03 parts by mass or more, and more preferably 0.05 parts by mass or more, relative to 100 parts by mass of the (meth) acrylate polymer (a). When the lower limit of the content of the crosslinking agent (C) is as described above, the crosslinking agent adduct of the polyrotaxane compound (B) can be formed well, and the stress relaxation property of the obtained adhesive can be further improved. The upper limit of the content of the crosslinking agent (C) is preferably 2.5 parts by mass or less, more preferably 2.0 parts by mass or less, particularly preferably 1.5 parts by mass or less, and further preferably 0.5 parts by mass or less, based on 100 parts by mass of the (meth) acrylate polymer (a). When the upper limit of the content of the crosslinking agent (C) is as described above, the degree of crosslinking can be made appropriate, and the step following property of the obtained adhesive can be satisfactorily ensured.
(1-4) active energy ray-curable component (D)
The adhesive composition P may further contain an active energy ray-curable component (D). The adhesive containing the active energy ray-curable component (D) is more excellent in step following property before curing, and the adhesive after curing is more excellent in step following property under high temperature and high humidity conditions.
The active energy ray-curable component (D) is cured by irradiation with an active energy ray, and is not particularly limited as long as the above-described effects can be obtained, and may be any of a monomer, an oligomer, or a polymer, or a mixture thereof. Among them, polyfunctional acrylate monomers having more excellent blister resistance are preferably used.
Examples of the polyfunctional acrylate monomer include bifunctional types such as 1, 4-butanediol di (meth) acrylate, 1, 6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, neopentyl glycol adipate di (meth) acrylate, neopentyl glycol hydroxypivalate di (meth) acrylate, dicyclopentyl di (meth) acrylate, caprolactone-modified dicyclopentenyl di (meth) acrylate, ethylene oxide-modified phosphoric acid di (meth) acrylate, di (acryloyloxyethyl) isocyanurate, allylated cyclohexyl di (meth) acrylate, ethoxylated bisphenol a diacrylate, and 9, 9-bis [4- (2-acryloyloxyethoxy) phenyl ] fluorene; trifunctional types such as trimethylolpropane tri (meth) acrylate, dipentaerythritol tri (meth) acrylate, propionic acid-modified dipentaerythritol tri (meth) acrylate, pentaerythritol tri (meth) acrylate, propylene oxide-modified trimethylolpropane tri (meth) acrylate, tris (acryloyloxyethyl) isocyanurate, and e-caprolactone-modified tris- (2- (meth) acryloyloxyethyl) isocyanurate; tetrafunctional types such as diglycerin tetra (meth) acrylate and pentaerythritol tetra (meth) acrylate; pentafunctional types such as propionic acid-modified dipentaerythritol penta (meth) acrylate; and hexafunctional types such as dipentaerythritol hexa (meth) acrylate and caprolactone-modified dipentaerythritol hexa (meth) acrylate. Among them, from the viewpoint of poor step followability of the obtained adhesive under high temperature and high humidity conditions, a bifunctional or trifunctional polyfunctional acrylate monomer is preferable, trimethylolpropane di (meth) acrylate or trimethylolpropane tri (meth) acrylate is particularly preferable, and trimethylolpropane diacrylate or trimethylolpropane triacrylate is further preferable. These may be used alone or in combination of two or more. In addition, from the viewpoint of compatibility with the (meth) acrylate polymer (a), a polyfunctional acrylate monomer having a molecular weight of less than 1000 is preferable as the polyfunctional acrylate monomer.
From the viewpoint of improving the cohesive force of the obtained adhesive and further improving the step following property under high temperature and high humidity conditions, the lower limit of the content of the active energy ray-curable component (D) in the adhesive composition P is preferably 1 part by mass or more, more preferably 2 parts by mass or more, and particularly preferably 3 parts by mass or more, relative to 100 parts by mass of the (meth) acrylate polymer (a). On the other hand, the upper limit of the content is preferably 20 parts by mass or less, more preferably 18 parts by mass or less, and particularly preferably 15 parts by mass or less, from the viewpoint of obtaining the warpage-suppressing effect.
(1-5) various additives
The adhesive composition P may also contain, as required, various additives commonly used in acrylic adhesives, such as silane coupling agents, tackifiers, antioxidants, light stabilizers, softeners, fillers, refractive index modifiers, and the like. The polymerization solvent or the dilution solvent described later is not included in the additives constituting the adhesive composition P.
Here, when the adhesive composition P contains the active energy ray-curable component (D) and uses ultraviolet rays as active energy rays, it preferably contains a photopolymerization initiator. By containing the photopolymerization initiator, the active energy ray-curable component (D) can be cured efficiently, and the time for polymerization curing and the amount of ultraviolet irradiation can be reduced.
As the photopolymerization initiator (D), examples thereof include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin n-butyl ether, benzoin isobutyl ether, acetophenone, dimethylaminoacetophenone, 2-dimethoxy-2-phenylacetophenone, 2-diethoxy-2-phenylacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-hydroxycyclohexylphenyl ketone, 2-methyl-1- [4- (methylthio) phenyl ] -2-morpholinyl-1-one, 4- (2-hydroxyethoxy) phenyl-2- (hydroxy-2-propyl) ketone, benzophenone, p-phenylbenzophenone, benzophenone, and 4,4' -diethylaminobenzophenone, dichlorobenzophenone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-t-butylanthraquinone, 2-aminoanthraquinone, 2-methylthioxanthone, 2-ethylthioxanthone, 2-chlorothioxanthone, 2, 4-dimethylthioxanthone, 2, 4-diethylthioxanthone, benzil dimethyl ketal, acetophenone dimethyl ketal, p-dimethylaminobenzoate, oligo [ 2-hydroxy-2-methyl-1- [4- (1-methylvinyl) phenyl ] propanone ], 2,4, 6-trimethylbenzoyl-diphenyl-phosphine oxide, bis (2, 4, 6-trimethylbenzoyl) -phenyl phosphine oxide and the like. These may be used alone or in combination of two or more.
The lower limit of the content of the photopolymerization initiator in the adhesive composition P is preferably 1 part by mass or more, particularly preferably 4 parts by mass or more, and more preferably 8 parts by mass or more, per 100 parts by mass of the active energy ray-curable component (D). The upper limit of the content of the photopolymerization initiator is preferably 30 parts by mass or less, particularly preferably 20 parts by mass or less, and more preferably 15 parts by mass or less.
(2) Preparation of adhesive composition
The adhesive composition P can be prepared by: the (meth) acrylate polymer (a) is prepared, and the obtained (meth) acrylate polymer (a) is mixed with the polyrotaxane compound (B), and if necessary, a crosslinking agent (C), an active energy ray-curable component (D), an additive, and the like are added.
The (meth) acrylate polymer (a) can be produced by polymerizing a mixture of monomers constituting the polymer by a general radical polymerization method. The polymerization of the (meth) acrylate polymer (a) is preferably carried out by a solution polymerization method using a polymerization initiator as necessary. However, the present invention is not limited thereto, and polymerization may be carried out without a solvent. Examples of the polymerization solvent include ethyl acetate, n-butyl acetate, isobutyl acetate, toluene, acetone, hexane, and methyl ethyl ketone, and two or more of them may be used simultaneously.
Examples of the polymerization initiator include azo compounds and organic peroxides, and two or more of them may be used simultaneously. As the azo-based compound, there may be mentioned, examples thereof include 2,2' -azobisisobutyronitrile, 2' -azobis (2-methylbutyronitrile), 1' -azobis (cyclohexane-1-carbonitrile), 2' -azobis (2, 4-dimethylvaleronitrile), 2' -azobis (2, 4-dimethyl-4-methoxyvaleronitrile) dimethyl 2,2' -azobis (2-methylpropionate), 4' -azobis (4-cyanovaleric acid), 2' -azobis (2-hydroxymethylpropionitrile), 2' -azobis [2- (2-imidazolin-2-yl) propane ], and the like.
Examples of the organic peroxide include benzoyl peroxide, tert-butyl peroxybenzoate, cumene hydroperoxide, diisopropyl peroxydicarbonate, di-n-propyl peroxydicarbonate, di (2-ethoxyethyl) peroxydicarbonate, tert-butyl peroxyneodecanoate, tert-butyl peroxypivalate, peroxy (3, 5-trimethylhexanoyl) peroxide, dipropionyl peroxide, and diacetyl peroxide.
In the polymerization step, a chain transfer agent such as 2-mercaptoethanol is added to adjust the weight average molecular weight of the obtained polymer.
After the (meth) acrylate polymer (a) is obtained, the polyrotaxane compound (B) and, if necessary, the crosslinking agent (C), the active energy ray-curable component (D), the diluting solvent, the additive and the like are added to the solution of the (meth) acrylate polymer (a), and the mixture is sufficiently mixed, thereby obtaining the adhesive composition P (coating solution) diluted with the solvent. In addition, when a solid substance is used or when the solid substance is precipitated when the solid substance is mixed with another component in an undiluted state, each of the above components may be dissolved or diluted in a diluting solvent in advance and then mixed with another component.
Examples of the diluting solvent include aliphatic hydrocarbons such as hexane, heptane and cyclohexane, aromatic hydrocarbons such as toluene and xylene, halogenated hydrocarbons such as methylene chloride and vinyl chloride, alcohols such as methanol, ethanol, propanol, butanol and 1-methoxy-2-propanol, ketones such as acetone, methyl ethyl ketone, 2-pentanone, isophorone and cyclohexanone, esters such as ethyl acetate and butyl acetate, and cellosolve solvents such as ethyl cellosolve.
The concentration and viscosity of the coating solution prepared in this manner are not particularly limited as long as they are within a range in which coating can be performed, and can be appropriately selected according to the situation. For example, the adhesive composition P is diluted so that the concentration thereof becomes 10 to 60 mass%. In addition, when obtaining the coating solution, the addition of a diluting solvent or the like is not an essential condition, and if the adhesive composition P has a coatable viscosity or the like, the addition of a diluting solvent may not be necessary. In this case, the adhesive composition P is a coating solution in which the polymerization solvent of the (meth) acrylate polymer (a) is directly used as a dilution solvent.
[ Adhesives ]
The pressure-sensitive adhesive of the present embodiment can be obtained by crosslinking the pressure-sensitive adhesive composition P described above. The crosslinking of the adhesive composition P can generally be carried out by heat treatment. Further, the drying treatment when evaporating the diluent solvent or the like from the coating film of the adhesive composition P applied to a desired object may also be used as the heating treatment.
The heating temperature for the heating treatment is preferably 50 to 150 ℃, particularly preferably 70 to 120 ℃. The heating time is preferably 10 seconds to 10 minutes, and particularly preferably 50 seconds to 5 minutes.
After the heat treatment, an aging period of about 1 to 2 weeks may be set at normal temperature (e.g., 23 ℃ C., 50% RH) as necessary. When the curing period is required, an adhesive is formed after the curing period, and when the curing period is not required, an adhesive is formed after the heat treatment is completed.
When the adhesive composition P contains the crosslinking agent (C), the (meth) acrylate polymer (a) and the polyrotaxane compound (B) are crosslinked by the above-mentioned heat treatment (and curing) through the crosslinking agent (C). The adhesive obtained in this way is more excellent in step following property.
In addition, in the case where the adhesive composition P contains the active energy ray-curable component (D), the adhesive composition P may be applied to a desired object and subjected to a heat treatment as described above, and then the adhesive composition P is cured by irradiation with an active energy ray to form an adhesive (adhesive layer). This further improves the step following property in the initial stage.
The lower limit of the gel fraction of the adhesive of the present embodiment is 20% or more, preferably 30% or more, and particularly preferably 40% or more. When the lower limit of the gel fraction of the adhesive is as described above, the cohesive force of the adhesive is improved, and the step following property under high-temperature and high-humidity conditions is further improved. The upper limit of the gel fraction of the adhesive of the present embodiment is 95% or less, preferably 85% or less, particularly preferably 75% or less, and more preferably 65% or less. When the upper limit of the gel fraction of the adhesive is as described above, the adhesive does not become too hard, and the initial step following property becomes excellent. Here, the method of measuring the gel fraction of the adhesive is shown in the test examples described below.
When the adhesive composition P contains the active energy ray-curable component (D), the adhesive preferably satisfies the gel fraction described above after irradiation with active energy rays.
[ adhesive sheet ]
The adhesive sheet of the present embodiment has at least an adhesive layer composed of the adhesive, and is preferably formed by laminating a release sheet on one surface or both surfaces of the adhesive layer.
Fig. 1 shows a specific structure of an example of the adhesive sheet of the present embodiment.
As shown in fig. 1, the adhesive sheet 1 of one embodiment is composed of two release sheets 12a and 12b and an adhesive 11 sandwiched between the two release sheets 12a and 12b so as to be in contact with the release surfaces of the two release sheets 12a and 12b. The release surface of the release sheet in the present specification means a surface having releasability in the release sheet, and includes any of a surface subjected to a release treatment and a surface showing releasability even if the release treatment is not performed.
(1) Constituent elements
(1-1) adhesive agent layer
The adhesive layer 11 is composed of the adhesive described above, that is, an adhesive obtained by crosslinking the adhesive composition P.
The lower limit of the thickness (value measured according to JIS K7130) of the adhesive layer 11 of the adhesive sheet 1 of the present embodiment is preferably 10 μm or more, more preferably 25 μm or more, and particularly preferably 50 μm or more. When the lower limit of the thickness of the adhesive layer 11 is as described above, a desired adhesive force is easily exhibited, and further, sufficient level difference followability to a normal level difference, for example, a level difference due to a printed layer of the display constituent member can be secured.
The upper limit of the thickness of the adhesive layer 11 is preferably 1000 μm or less, more preferably 500 μm or less, and particularly preferably 300 μm or less. If the upper limit of the thickness of the adhesive layer 11 is as described above, the workability is good. The adhesive layer 11 may be formed of a single layer or may be formed by stacking a plurality of layers.
(1-2) Release sheet
The release sheets 12a, 12b protect the adhesive layer 11 until the time of using the adhesive sheet 1, and are released when the adhesive sheet 1 (adhesive layer 11) is used. In the adhesive sheet 1 of the present embodiment, one or both of the release sheets 12a and 12b are not necessarily required.
Examples of the release sheets 12a and 12b include a polyethylene film, a polypropylene film, a polybutylene film, a polybutadiene film, a polymethylpentene film, a polyvinyl chloride film, a vinyl chloride copolymer film, a polyethylene terephthalate film, a polyethylene naphthalate film, a polybutylene terephthalate film, a polyurethane film, an ethylene-vinyl acetate film, an ionomer resin film, an ethylene- (meth) acrylic acid copolymer film, an ethylene- (meth) acrylate copolymer film, a polystyrene film, a polycarbonate film, a polyimide film, and a fluororesin film. In addition, crosslinked films of these films may also be used. Further, a laminated film of these films may be used.
The release surfaces of the release sheets 12a and 12b (particularly, the surfaces in contact with the adhesive layer 11) are preferably subjected to a release treatment. Examples of the release agent used for the release treatment include alkyd based, silicone based, fluorine based, unsaturated polyester based, polyolefin based, and wax based release agents. In addition, among the release sheets 12a and 12b, it is preferable that one release sheet is a heavy release type release sheet having a large release force, and the other release sheet is a light release type release sheet having a small release force.
The thickness of the release sheets 12a and 12b is not particularly limited, but is usually about 20 to 150 μm.
(2) Physical Properties (haze value)
The adhesive layer 11 (thickness: 50 μm) of the adhesive sheet 1 of the present embodiment has a haze value at 23 ℃ of preferably 8% or less, particularly preferably 7% or less, and further preferably 5% or less. Further, when the adhesive sheet 1 of the present embodiment (thickness of the adhesive layer 11: 50 μm) is stored at-40 ℃ for 3 days and then left at 23 ℃ for 1 hour, the haze value of the adhesive layer 11 is preferably 8% or less, particularly preferably 7% or less, and further preferably 5% or less. By setting the haze value of the adhesive layer 11 to the above value, the light transmittance is excellent both in a normal temperature environment and a low temperature environment, and thus the adhesive layer is suitable for optical use. In particular, even if the adhesive layer 11 is thick and 50 μm, it is excellent in light transmittance, and therefore, it is suitable for the case where an optical member having a level difference is used as an adherend. The adhesive sheet 1 of the present embodiment can achieve the low haze value as described above by using the adhesive composition P.
On the other hand, the lower limit of the haze value at 23 ℃ of the adhesive layer 11 (thickness: 50 μm) of the adhesive sheet 1 of the present embodiment is not particularly limited, but is preferably 0% or more, and more preferably 0.1% or more. The lower limit of the haze value of the adhesive layer 11 after the adhesive sheet 1 of the present embodiment (thickness of the adhesive layer 11: 50 μm) is stored at-40 ℃ for 3 days is also not particularly limited, but is preferably 0% or more, and more preferably 0.1% or more. Here, the haze value in the present specification is a value measured in accordance with JIS K7136: 2000.
When the adhesive composition P contains the active energy ray-curable component (D), the adhesive layer 11 preferably satisfies the above-described haze value after irradiation with an active energy ray.
(3) Production of adhesive sheet
As one production example of the adhesive sheet 1, a coating solution of the above-described adhesive composition P is applied to the release surface of one release sheet 12a (or 12 b), heat treatment is performed to thermally crosslink the adhesive composition P to form a coating layer, and then the release surface of the other release sheet 12b (or 12 a) is laminated on the coating layer. When the curing period is required, the coating layer becomes the adhesive layer 11 after the curing period, and when the curing period is not required, the coating layer directly becomes the adhesive layer 11. Through the above steps, the adhesive sheet 1 can be obtained. Conditions for the heat treatment and aging are as described above.
As another production example of the adhesive sheet 1, a coating solution of the adhesive composition P is applied to the release surface of one release sheet 12a, and heat treatment is performed to thermally crosslink the adhesive composition P to form a coating layer, thereby obtaining a release sheet 12a with a coating layer. The coating solution of the adhesive composition P is applied to the release surface of the other release sheet 12b, and heat treatment is performed to thermally crosslink the adhesive composition P to form a coating layer, thereby obtaining a release sheet 12b with a coating layer. Then, the coated release sheet 12a and the coated release sheet 12b are bonded to each other so that both the coating layers are in contact with each other. When the curing period is required, the laminated coating layer becomes the adhesive layer 11 after the curing period, and when the curing period is not required, the laminated coating layer directly becomes the adhesive layer 11. Through the above steps, the adhesive sheet 1 is obtained. According to this production example, even if the adhesive layer 11 is thick, stable production can be performed.
As a method for applying the coating liquid of the adhesive composition P, for example, a bar coating method, a blade coating method, a roll coating method, a blade coating method, a die coating method, a gravure coating method, or the like can be used.
[ use ]
The pressure-sensitive adhesive sheet 1 of the present embodiment can be used for various applications, and among them, it is preferably used for optical applications, and particularly preferably used for optical applications intended to be used in an environment of-40 ℃. Further, since the adhesive sheet 1 of the present embodiment is also excellent in step following property, it can be preferably used for application to a member having a step on the adhesive agent layer 11 side. Further, the present invention can be preferably used for bonding two optical hard plates to each other. As the optical application, for example, a display (display) or a solar cell module can be preferably cited, a display can be particularly preferably cited, and a display having a step difference on the adhesive agent layer 11 side can be further preferably cited.
In the application of bonding two optical hard sheets to each other, one or both of the hard sheets may have a step difference on the adhesive layer 11 side, or both of the hard sheets may have no step difference. Even in the case of a hard sheet having no level difference, the adhesive agent layer 11 of the present embodiment has high flexibility due to the characteristic of excellent level difference followability, and thus a hard sheet which is not bent at the time of bonding can be bonded well.
The following description will be given by taking a display as an example, but the present invention is not limited thereto.
Fig. 2 shows an example of a display obtained by using the adhesive sheet 1 of the present embodiment. The display body 2 of the present embodiment is configured to have the following structure: the adhesive layer 11 includes a first display body constituting member 21 (one display body constituting member), a second display body constituting member 22 (the other display body constituting member) having a step at least on the surface on the bonding side, and the adhesive layer being interposed between the first display body constituting member 21 and the second display body constituting member 22 and bonding the first display body constituting member and the second display body constituting member to each other. In the display 2 of the present embodiment, the first display component member 21 has a step on the surface on the adhesive layer 11 side, specifically, a step due to the printed layer 3.
Examples of the display 2 include a Liquid Crystal Display (LCD), a Light Emitting Diode (LED) display, an organic electroluminescence (organic EL) display, and an electronic paper, and may be a touch panel. The display 2 may be a member that constitutes a part of them.
The adhesive layer 11 in the display 2 is the adhesive layer 11 itself of the adhesive sheet 1 or a layer cured by irradiation of an active energy ray to the adhesive layer 11 of the adhesive sheet 1.
The first display element constituting member 21 is preferably a protective panel made of a laminate including a glass plate, a plastic plate, and the like, in addition to a glass plate, a plastic plate, and the like. In this case, the print layer 3 is usually formed in a frame shape on the adhesive agent layer 11 side in the first display composition member 21.
The glass plate is not particularly limited, and examples thereof include chemically strengthened glass, alkali-free glass, quartz glass, soda-lime glass, barium-strontium-containing glass, aluminosilicate glass, lead glass, borosilicate glass, barium borosilicate glass, and the like. The thickness of the glass plate is not particularly limited, but is usually 0.1 to 5mm, preferably 0.2 to 2mm.
The plastic plate is not particularly limited, and examples thereof include acrylic plates and polycarbonate plates. The thickness of the plastic sheet is not particularly limited, but is usually 0.2 to 5mm, preferably 0.4 to 3mm.
Further, various functional layers (a transparent conductive film, a metal layer, a silica layer, a hard coat layer, an antiglare layer, and the like) may be provided on one surface or both surfaces of the glass plate or the plastic plate, and an optical member may be laminated. In addition, the transparent conductive film and the metal layer may also be patterned.
The second display body constituting member 22 is preferably an optical member to be attached to the first display body constituting member 21, a display body module (for example, a Liquid Crystal (LCD) module, a Light Emitting Diode (LED) module, an organic electroluminescence (organic EL) module, or the like), an optical member as a part of the display body module, or a laminate including the display body module.
Examples of the optical member include an anti-scattering film, a polarizing plate (polarizing film), a polarizer, a retardation plate (retardation film), a viewing angle compensation film, a brightness enhancement film, a contrast enhancement film, a liquid crystal polymer film, a diffusion film, a semi-transmissive reflective film, and a transparent conductive film. Examples of the anti-scattering film include a hard coat film in which a hard coat layer is formed on one surface of a base film.
The material constituting the printed layer 3 is not particularly limited, and a known material for printing can be used. The lower limit of the thickness of the printed layer 3, that is, the height of the step is preferably 3 μm or more, more preferably 5 μm or more, particularly preferably 10 μm or more, and further preferably 30 μm or more. By setting the lower limit value to the above value, it is possible to sufficiently ensure concealment of the electric wiring lines and the like from the observer side. The upper limit is preferably 80 μm or less, more preferably 60 μm or less, and particularly preferably 40 μm or less. By setting the upper limit value to the above value, it is possible to prevent the step difference following property of the adhesive layer 11 to the printed layer 3 from being deteriorated.
In order to manufacture the display 2, one release sheet 12a of the adhesive sheet 1 is peeled off, and the adhesive layer 11 exposed in the adhesive sheet 1 is bonded to the surface of the first display constituting member 21 on which the printed layer 3 is present, as an example. In this case, since the adhesive layer 11 is excellent in the step following property, generation of a gap or floating in the vicinity of the step caused by the printed layer 3 can be suppressed.
Then, the other release sheet 12b is peeled off from the adhesive layer 11 of the adhesive sheet 1, and the adhesive layer 11 exposed in the adhesive sheet 1 is bonded to the second display constituent member 22. As another example, the order of attaching the first display body constituting member 21 and the second display body constituting member 22 may be changed.
Here, in the case where the adhesive composition P contains the active energy ray-curable component (D), after the laminate of the first display structure constituting member 21 and the adhesive agent layer 11 is bonded to the second display structure constituting member 22, the adhesive agent layer 11 is preferably cured by irradiating the adhesive agent layer 11 with an active energy ray through the first display structure constituting member 21 and/or the second display structure constituting member 22. This makes the step following property under high-temperature and high-humidity conditions more excellent.
The active energy ray is an active energy ray having an energy quantum in an electromagnetic wave or a charged particle beam, and specifically, an ultraviolet ray, an electron beam, or the like can be mentioned. Among the active energy rays, ultraviolet rays which are easy to handle are particularly preferable.
The ultraviolet irradiation can use high pressureA mercury lamp, fusion H lamp (fusion H lamp), xenon lamp, etc., and the irradiation amount of the ultraviolet ray is preferably 50 to 1000mW/cm in illuminance meter 2 Left and right. The light amount is preferably 50 to 10000mJ/cm 2 More preferably 80 to 5000mJ/cm 2 Particularly preferably 300 to 2000mJ/cm 2 . On the other hand, the irradiation with the electron beam can be performed using an electron beam accelerator or the like, and the irradiation amount with the electron beam is preferably about 10 to 1000 krad.
The display 2 can suppress the haze value of the adhesive agent layer 11 to be low in a normal temperature environment, and can suppress the increase in the haze value of the adhesive agent layer 11 even in a low temperature environment, for example, an environment of-40 ℃. Specifically, the haze value of each can be suppressed to 8% or less. Therefore, the adhesive layer 11 is excellent in light transmittance both in the normal temperature environment and in the low temperature environment, and the visibility of the display 2 can be sufficiently ensured. In addition, even if the adhesive layer 11 is thick, the above-described effects can be exhibited.
In addition, in the display 2, since the adhesive agent layer 11 is excellent in the step following property under high temperature and high humidity conditions, even when the display 2 is left to stand under high temperature and high humidity conditions (for example, 85 ℃, 85% rh), for example, the generation of bubbles, floating, peeling, and the like in the vicinity of the step can be suppressed.
The position of use of the adhesive sheet 1 (adhesive layer 11) of the present embodiment in the display is not limited to the above-described example. For example, the adhesive sheet 1 of the present embodiment may be used to bond display body constituting members having no step difference as described above to each other.
The embodiments described above are described for easy understanding of the present invention, and are not described for limiting the present invention. Therefore, each element disclosed in the above embodiments also covers all design changes or equivalents that fall within the technical scope of the present invention.
For example, one or both of the release sheets 12a and 12b in the adhesive sheet 1 may be omitted, or a desired optical member may be laminated instead of the release sheets 12a and/or 12b. Further, the first display body constituting member 21 may have a step other than the printed layer 3. Further, not only the first display element constituting member 21 but also the second display element constituting member 22 may have a step difference on the adhesive agent layer 11 side.
Examples
The present invention will be described in more detail with reference to examples below, but the scope of the present invention is not limited to these examples and the like.
[ example 1]
1. Preparation of (meth) acrylate polymers
A (meth) acrylate polymer was prepared by copolymerizing 80 parts by mass of 2-ethylhexyl acrylate, 5 parts by mass of 2-phenoxyethyl acrylate, and 15 parts by mass of 2-hydroxyethyl acrylate by a solution polymerization method. The molecular weight of the (meth) acrylate polymer (a) was measured by the method described below, and as a result, the weight average molecular weight (Mw) was 60 ten thousand.
2. Preparation of adhesive composition
100 parts by mass (in terms of solid content; the same applies hereinafter) of the (meth) acrylate Polymer (A) obtained in step 1, a polyrotaxane compound (B) (manufactured by Advanced plastics Inc., product name "SERM Super Polymer SH3400P", straight-chain molecule: polyethylene glycol, cyclic molecule: α -cyclodextrin having hydroxypropyl and caprolactone chains, end capping group: adamantyl, weight average molecular weight (Mw) of 70 ten thousand, hydroxyl value of 72 mgKOH/g) of 5.0 parts by mass, and 0.3 parts by mass of trimethylolpropane-modified toluene diisocyanate (Nippon Polyurethane Industry Co., manufactured by Ltd., product name "Coronate L") as a crosslinking agent (C) were mixed, sufficiently stirred, and diluted with methyl ethyl ketone to obtain a coating solution of an adhesive composition.
Table 1 shows the respective compounding ratios (solid content equivalent) of the adhesive compositions when the (meth) acrylate polymer (a) is 100 parts by mass (solid content equivalent). The abbreviations and the like shown in table 1 are as follows.
[ (meth) acrylic acid ester Polymer (A) ]
2EHA: 2-ethylhexyl acrylate
PEA: 2-Phenoxyethyl acrylate
HEA: 2-Hydroxyethyl acrylate
Bz is as follows: acrylic acid benzyl ester
BA: acrylic acid n-butyl ester
AA: acrylic Acid (AA)
[ crosslinking agent (C) ]
TDI: trimethylolpropane-modified tolylene diisocyanate (product name "Coronate L", manufactured by Nippon Polyurethane Industry Co., ltd.)
And (3) epoxy: n, N, N ', N' -tetraglycidyl-m-xylylenediamine (manufactured by Soken Chemical & Engineering Co., ltd., product name "E-AX")
3. Production of adhesive sheet
The coating solution of the adhesive composition obtained in the above step 2 was coated on the release-treated surface of a heavy release type release sheet (manufactured by linetec Corporation, product name "SP-PET 752150") obtained by subjecting one surface of a polyethylene terephthalate film to a release treatment using a silicone-based release agent, using a blade coater. Then, the coating layer was subjected to a heat treatment at 100 ℃ for 4 minutes, thereby forming a coating layer.
Next, the coating layer on the heavy-release type release sheet obtained above was bonded to a light-release type release sheet (product name "SP-PET382120", manufactured by linec Corporation) obtained by peeling one surface of a polyethylene terephthalate film with a silicone type release agent, in such a manner that the peeled surface of the light-release type release sheet was in contact with the coating layer, and the sheet was aged at 23 ℃ and 50% rh for 7 days, thereby producing an adhesive sheet having a structure of a heavy-release type release sheet/adhesive layer (thickness: 50 μm)/light-release type release sheet.
The thickness of the adhesive agent layer is a value measured by using a constant pressure thickness measuring instrument (TECLOCK co., ltd., product name "PG-02") in accordance with JIS K7130.
Examples 2 to 8 and comparative examples 1 to 8
An adhesive sheet was produced in the same manner as in example 1, except that the kind and ratio of each monomer constituting the (meth) acrylate polymer (a), the weight average molecular weight of the (meth) acrylate polymer (a), the blending amount of the polyrotaxane compound (B), and the kind and blending amount of the crosslinking agent (C) were changed as shown in table 1.
[ example 9]
1. Preparation of (meth) acrylate polymers
The (meth) acrylate polymer (a) was prepared by copolymerizing 77 parts by mass of 2-ethylhexyl acrylate, 15 parts by mass of 2-phenoxyethyl acrylate, and 8 parts by mass of 2-hydroxyethyl acrylate by a solution polymerization method. The molecular weight of the (meth) acrylate polymer (a) was measured by the method described below, and as a result, the weight average molecular weight (Mw) was 57 ten thousand.
2. Preparation of adhesive composition
100 parts by mass of the (meth) acrylate Polymer (a) obtained in step 1, polyethylene glycol as a linear molecule, polyethylene glycol as a cyclic molecule, alpha-cyclodextrin having a hydroxypropyl and caprolactone chain, adamantyl as a terminal group, 70 ten thousand weight average molecular weight (Mw), and 72mgKOH/g as a hydroxyl value, 5.0 parts by mass of trimethylolpropane-modified toluene diisocyanate (Nippon Polyurethane Industry co, ltd. As a crosslinking agent (C), 0.3 parts by mass of trimethylolpropane triacrylate as an active energy ray-curable component (D), and 0.6 parts by mass of 1-hydroxycyclohexyl phenyl ketone as a photopolymerization initiator were mixed, sufficiently stirred, and diluted with methyl ethyl ketone to obtain a coating solution of the adhesive composition.
3. Production of adhesive sheet
An adhesive sheet was produced in the same manner as in example 1, except that the coating solution of the adhesive composition obtained in the above step 2 was used.
Here, the weight average molecular weight (Mw) is a weight average molecular weight in terms of polystyrene measured by Gel Permeation Chromatography (GPC) under the following conditions (GPC measurement).
< measurement Condition >
"measuring apparatus: HLC-8320, manufactured by TOSOH CORPORATION
"GPC chromatography column (by: TOSOH CORPORATION, inc
TSK gel super H-H
TSK gel super HM-H
TSK gel super H2000
"determination of solvent: tetrahydrofuran (THF)
"measurement temperature: 40 deg.C
[ test example 1] (measurement of gel fraction)
The adhesive sheets produced in examples and comparative examples were cut into 80mm × 80mm, the adhesive layers were wrapped in a polyester mesh (mesh size 200), the masses thereof were weighed with a precision balance, and the masses of the adhesive itself were calculated by subtracting the masses of the mesh alone. The mass at this time is denoted as M1.
Subsequently, the adhesive wrapped in the polyester mesh was immersed in ethyl acetate at room temperature (23 ℃ C.) for 24 hours. The adhesive was then removed, air-dried at a temperature of 23 ℃ and a relative humidity of 50% for 24 hours, and further dried in an oven at 80 ℃ for 12 hours. After drying, the mass was weighed with a precision balance, and the mass of the above-mentioned mesh alone was subtracted, thereby calculating the mass of the adhesive itself. The mass at this time is denoted as M2. The gel fraction (%) is represented by (M2/M1) × 100. The results are shown in Table 2.
In addition, with respect to the adhesive sheet of example 9, the gel fraction after irradiation of the adhesive layer with active energy rays (ultraviolet rays; UV) was measured (irradiation from the side of the heavy-release type release sheet). The irradiation conditions of the active energy ray are as follows.
< conditions of irradiation with active energy rays >
Mercury high-pressure lamp
Illuminance of 200mW/cm 2 Quantity of light 1000mJ/cm 2
"UV illuminance" photometer used "UVPF-A1" manufactured by EYE GRAPHICS Co., ltd "
[ test example 2] (measurement of haze value)
(1) Haze value at 23 DEG C
The light-release type release sheet was peeled from the adhesive sheets produced in examples and comparative examples, and the exposed adhesive layer was attached to soda-lime glass. Subsequently, the heavy-release sheet was peeled off from the adhesive layer, and the haze value (%) of the adhesive layer in the obtained laminate was measured at 23 ℃ using a haze meter (NIPPON DENSHOKU INDUSTRIES Co., LTD, product name "NDH-5000") in accordance with JIS K7136: 2000. The results are shown in Table 2.
In addition, the adhesive sheet of example 9 was attached to soda-lime glass in the same manner as described above, and then the adhesive layer was irradiated with active energy rays (ultraviolet rays) (irradiated from the side of the heavy-release type release sheet). Subsequently, the heavy-release sheet was peeled off, and the haze value (%) of the adhesive layer in the obtained laminate was measured at 23 ℃. The irradiation conditions of the active energy ray were the same as in test example 1.
(2) Haze value at-40 ℃
The light-release type release sheet was peeled from the adhesive sheets produced in examples and comparative examples, and the exposed adhesive layer was attached to soda-lime glass. The laminate was stored at-40 ℃ for 3 days and then allowed to stand at 23 ℃ for 1 hour. Next, the heavy-release type release sheet was peeled off from the adhesive layer, and the adhesive layer in the obtained laminate was laminated according to JIS K7136: 2000. the haze value (%) was measured using a haze meter (NIPPON DENSHOKU INDUSTRIES Co., LTD, product name "NDH-5000"). The results are shown in Table 2.
In addition, the adhesive sheet of example 9 was attached to soda-lime glass in the same manner as described above, and then the adhesive layer was irradiated with active energy rays (ultraviolet rays) (from the side of the heavy-release type release sheet). The resulting laminate was stored at-40 ℃ for 3 days and then left at 23 ℃ for 1 hour. Next, the heavy-release sheet was peeled off, and the haze value (%) of the adhesive agent layer in the obtained laminate was measured. The irradiation conditions of the active energy ray were the same as in test example 1.
[ test example 3] (evaluation of step-by-step followability)
On a glass plate (manufactured by NSG Precision Cells, inc., product name "burning glasOn the surface of the ink, s eagle XG ", 90mm vertical x 50mm horizontal x 0.5mm thick, an ultraviolet curable ink (Teikoku Printing Inks mfg. Co., ltd, product name" POS-911 ink ") was screen-printed in a frame shape (outer shape: 90mm in length by 50mm in width, 5mm in width). Then, ultraviolet rays (80W/cm) were irradiated 2 2 metal halogen lamps with a lamp height of 15cm and a belt speed of 10 to 15 m/min), and curing the printed ultraviolet curable ink to produce a cured product having a step difference (height of step difference: 30 μm) of glass plate with segment difference.
The light-release type release sheet was peeled from the adhesive sheets produced in examples and comparative examples, and the exposed adhesive layer was bonded to an easy-adhesion layer of a polyethylene terephthalate (PET) film (TOYOBO co., ltd., product name "PET a4300" with a thickness of 100 μm) having the easy-adhesion layer. Next, the heavy-release sheet was peeled off to expose the adhesive layer, and the adhesive layer was laminated on each step glass plate so as to cover the entire frame-shaped printed surface using a laminator (product name "LPD3214" manufactured by fujiapla inc.). Then, the mixture was autoclaved at 50 ℃ and 0.5MPa for 30 minutes and allowed to stand at 23 ℃ and 50% RH for 24 hours under normal pressure.
In addition, with respect to the adhesive sheet of example 9, the adhesive layer was irradiated with active energy rays (ultraviolet rays) through the PET film to cure the adhesive layer. The irradiation conditions of the active energy ray were the same as in test example 1.
Subsequently, the samples were stored under high temperature and high humidity conditions of 85 ℃ and 85% RH for 72 hours (durability test), and then taken out to an environment of 23 ℃ and 50% RH. Then, the adhesive layer (particularly, the vicinity of the level difference caused by the printed layer) was visually confirmed and the level difference following property was evaluated by the following criteria. The results are shown in Table 2.
Excellent: no bubble, floating, and peeling were observed in the vicinity of the level difference.
O: bubbles having a diameter of 0.2mm or less were observed in the vicinity of the level difference, and neither floating nor peeling was observed.
X: bubbles having a diameter exceeding 0.2mm were observed near the step, and the bubble was floated and peeled off.
[ Table 1]
Figure BDA0002150930110000301
[ Table 2]
Figure BDA0002150930110000311
As is clear from table 2, the adhesive sheets obtained in the examples had low haze values both in the normal temperature environment and in the low temperature environment, and also had excellent step following properties.
Industrial applicability
The adhesive composition, the adhesive and the adhesive sheet of the present invention can be suitably used for bonding a protective panel having a step difference to a desired display member constituting member in a display member (for example, a vehicle-mounted display) which is assumed to be used in a low temperature environment such as-40 ℃.

Claims (8)

1. An adhesive composition comprising a (meth) acrylate polymer (A) and a polyrotaxane compound (B),
the (meth) acrylate polymer (A) contains an aromatic ring-containing monomer and a reactive functional group-containing monomer as monomer units constituting the polymer;
the content of the aromatic ring-containing monomer as a structural monomer unit in the (meth) acrylate polymer (A) is 2.5 mass% or more and 30 mass% or less;
the content of the reactive functional group-containing monomer as a structural monomer unit in the (meth) acrylate polymer (A) is 8 to 30 mass%.
2. The adhesive composition according to claim 1, wherein the content of the polyrotaxane compound (B) in the adhesive composition is 1 to 20 parts by mass with respect to 100 parts by mass of the (meth) acrylate polymer (a).
3. The adhesive composition according to claim 1 or 2, which contains a crosslinking agent (C).
4. An adhesive which is obtained by crosslinking the adhesive composition according to any one of claims 1 to 3.
5. An adhesive sheet comprising two release sheets and an adhesive layer sandwiched between the release sheets so as to be in contact with release surfaces of the two release sheets,
the adhesive layer is composed of the adhesive according to claim 4.
6. Use of the adhesive sheet according to claim 5 for optical use.
7. Use of the adhesive sheet according to claim 6, wherein the adhesive sheet is for optical use which is supposed to be used in an environment of-40 ℃.
8. An adhesive sheet comprising an adhesive layer, characterized in that,
the adhesive layer has a haze value of 8% or less at 23 ℃,
the haze value of the adhesive layer after the adhesive sheet is stored at-40 ℃ for 3 days is 8% or less.
CN201910701370.0A 2018-07-31 2019-07-31 Adhesive composition, adhesive and adhesive sheet Active CN110776857B (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2018-143867 2018-07-31
JP2018143867A JP7075845B2 (en) 2018-07-31 2018-07-31 Adhesive compositions, adhesives and adhesive sheets

Publications (2)

Publication Number Publication Date
CN110776857A CN110776857A (en) 2020-02-11
CN110776857B true CN110776857B (en) 2022-12-20

Family

ID=69383967

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201910701370.0A Active CN110776857B (en) 2018-07-31 2019-07-31 Adhesive composition, adhesive and adhesive sheet

Country Status (4)

Country Link
JP (1) JP7075845B2 (en)
KR (1) KR102632908B1 (en)
CN (1) CN110776857B (en)
TW (1) TWI798417B (en)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114729243A (en) * 2020-02-25 2022-07-08 琳得科株式会社 Adhesive composition, adhesive and adhesive sheet
CN111613795B (en) * 2020-04-26 2021-11-12 中山大学 Multifunctional binder for lithium-sulfur battery anode and preparation method thereof

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2016155911A (en) * 2015-02-24 2016-09-01 日東電工株式会社 Adhesive composition, adhesive layer, adhesive sheet, optical member with adhesive layer, and image display device
CN106433522A (en) * 2015-08-10 2017-02-22 琳得科株式会社 Adhesive composition, adhesive, adhesive sheet, and display body
JPWO2015030080A1 (en) * 2013-08-29 2017-03-02 日本カーバイド工業株式会社 Adhesive composition for polarizing plate, polarizing plate with adhesive, and display device

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP6888901B2 (en) 2015-08-10 2021-06-18 リンテック株式会社 Adhesive Compositions, Adhesives, Adhesive Sheets and Labels
JP2017179230A (en) 2016-03-31 2017-10-05 積水化学工業株式会社 Optical transparent adhesive sheet

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPWO2015030080A1 (en) * 2013-08-29 2017-03-02 日本カーバイド工業株式会社 Adhesive composition for polarizing plate, polarizing plate with adhesive, and display device
JP2016155911A (en) * 2015-02-24 2016-09-01 日東電工株式会社 Adhesive composition, adhesive layer, adhesive sheet, optical member with adhesive layer, and image display device
CN106433522A (en) * 2015-08-10 2017-02-22 琳得科株式会社 Adhesive composition, adhesive, adhesive sheet, and display body

Also Published As

Publication number Publication date
CN110776857A (en) 2020-02-11
TW202007747A (en) 2020-02-16
KR102632908B1 (en) 2024-02-05
KR20200014188A (en) 2020-02-10
TWI798417B (en) 2023-04-11
JP7075845B2 (en) 2022-05-26
JP2020019869A (en) 2020-02-06

Similar Documents

Publication Publication Date Title
TWI634186B (en) Adhesive sheet and laminated body
KR102271568B1 (en) Adhesive sheet, display body and method for producing thereof
CN103980820B (en) Pressure-sensitive adhesive composition, pressure-sensitive adhesive, and pressure-sensitive adhesive sheet
CN106318281B (en) Adhesive composition, adhesive sheet, and display
CN108690519B (en) Pressure-sensitive adhesive composition, pressure-sensitive adhesive sheet, and display
JP6525726B2 (en) Adhesive sheet and display
JP6356786B2 (en) Adhesive sheet and laminate
CN112442325A (en) Adhesive sheet and optical laminate
KR20200075738A (en) Adhesive sheet, display element, and method of producing display element
CN110776857B (en) Adhesive composition, adhesive and adhesive sheet
CN108410373B (en) Pressure-sensitive adhesive and pressure-sensitive adhesive sheet
JP6959749B2 (en) Adhesive sheet and display
JP7383448B2 (en) Adhesives, adhesive sheets, backlight units and display devices
CN112646507A (en) Display body and adhesive sheet
CN111471404B (en) Adhesive sheet, structure, and method for producing structure
JP2020105360A (en) Pressure-sensitive adhesive composition, pressure-sensitive adhesive, pressure-sensitive adhesive sheet, structure and method for producing structure
JP7426539B2 (en) Method of manufacturing the construct
WO2023047860A1 (en) Pressure-sensitive adhesive composition, pressure-sensitive adhesive, pressure-sensitive adhesive sheet, and laminate
WO2023100866A1 (en) Adhesive sheet and method for manufacturing adhesive sheet
JP2023150617A (en) Adhesive sheet and display body
JP2020073704A (en) Adhesive sheet and laminate
JP2018127625A (en) Active energy ray-curable adhesive sheet and laminate
CN113943542A (en) Adhesive composition, adhesive sheet, and display
JP2020114903A (en) Pressure sensitive adhesive compositions, pressure sensitive adhesives, pressure sensitive adhesive sheet, and display body
JP2018127631A (en) Active energy ray-curable adhesive sheet

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
GR01 Patent grant
GR01 Patent grant